Metalworking (rec.crafts.metalworking) Discuss various aspects of working with metal, such as machining, welding, metal joining, screwing, casting, hardening/tempering, blacksmithing/forging, spinning and hammer work, sheet metal work.

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Default Drilling 304 Stainless

I may have asked this before, but I'm slow:

I have some 304 sheet. I use it to make control-line model airplane
handles. Each handle needs to have about 20 1/16" or .050" holes drilled
in it, in a pair of tidy lines.

This stuff breaks my regular old HSS drill bits, and my drill hand-
sharpening mojo is pretty spotty at 1/16".

I'm using them in a drill press. The whole process feels weird -- it
feels like there's a skin on the metal which prevents the drill from
starting to cut unless I feed it fairly hard, but once broken through
doesn't cause much problem. Most of the time that I break a drill bit
it's because I'm feeding it "just a bit harder", then SPING -- I've
broken another bit.

Is there a better drill bit to use, or have I just doomed myself to
trouble? Is there a better flavor of _stainless_ to use? I understand
that 304 is difficult to work with, but it's what McMaster had in the
thickness I wanted; having experienced its joys, however, I'm ready to
consider something else.

I think my next step is to get a dozen 1/16" drill bits, but if there's
some magic material that'll help here, I'm listening.

--
My liberal friends think I'm a conservative kook.
My conservative friends think I'm a liberal kook.
Why am I not happy that they have found common ground?

Tim Wescott, Communications, Control, Circuits & Software
http://www.wescottdesign.com
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Default Drilling 304 Stainless

Tim Wescott fired this volley in
:

Is there a better drill bit to use, or have I just doomed myself to
trouble? Is there a better flavor of _stainless_ to use? I understand
that 304 is difficult to work with, but it's what McMaster had in the
thickness I wanted; having experienced its joys, however, I'm ready to
consider something else.


Are you center-punching the holes before drilling?

If so, there IS a "skin" to break through... you've work-hardened the piece
where it's punched.

A better strategy is to use a really short bit, and just drill.

LLoyd
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Default Drilling 304 Stainless


"Tim Wescott" wrote in
message
...
I may have asked this before, but I'm slow:

I have some 304 sheet. I use it to make
control-line model airplane
handles. Each handle needs to have about 20
1/16" or .050" holes drilled
in it, in a pair of tidy lines.

This stuff breaks my regular old HSS drill bits,
and my drill hand-
sharpening mojo is pretty spotty at 1/16".

I'm using them in a drill press. The whole
process feels weird -- it
feels like there's a skin on the metal which
prevents the drill from
starting to cut unless I feed it fairly hard,
but once broken through
doesn't cause much problem. Most of the time
that I break a drill bit
it's because I'm feeding it "just a bit harder",
then SPING -- I've
broken another bit.

Is there a better drill bit to use, or have I
just doomed myself to
trouble? Is there a better flavor of
_stainless_ to use? I understand
that 304 is difficult to work with, but it's
what McMaster had in the
thickness I wanted; having experienced its joys,
however, I'm ready to
consider something else.

I think my next step is to get a dozen 1/16"
drill bits, but if there's
some magic material that'll help here, I'm
listening.

--
My liberal friends think I'm a conservative
kook.
My conservative friends think I'm a liberal
kook.
Why am I not happy that they have found common
ground?

Tim Wescott, Communications, Control, Circuits &
Software
http://www.wescottdesign.com


Perhaps you could hone a very fine split point on
the drill?
That's tiny but could be done with a small diamond
file and
a steady stroke. It's worth a try....
pdk



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Default Drilling 304 Stainless

On 8/30/2012 7:59 PM, Tim Wescott wrote:
I may have asked this before, but I'm slow:

I have some 304 sheet. I use it to make control-line model airplane
handles. Each handle needs to have about 20 1/16" or .050" holes drilled
in it, in a pair of tidy lines.

This stuff breaks my regular old HSS drill bits, and my drill hand-
sharpening mojo is pretty spotty at 1/16".

I'm using them in a drill press. The whole process feels weird -- it
feels like there's a skin on the metal which prevents the drill from
starting to cut unless I feed it fairly hard, but once broken through
doesn't cause much problem. Most of the time that I break a drill bit
it's because I'm feeding it "just a bit harder", then SPING -- I've
broken another bit.

Is there a better drill bit to use, or have I just doomed myself to
trouble? Is there a better flavor of _stainless_ to use? I understand
that 304 is difficult to work with, but it's what McMaster had in the
thickness I wanted; having experienced its joys, however, I'm ready to
consider something else.

I think my next step is to get a dozen 1/16" drill bits, but if there's
some magic material that'll help here, I'm listening.


304 SS is junk stainless, but cheap. The reason it's so hard to cut is
an absence of sulphur in the alloy for lubrication. You have to get the
speed & feed just right to cut it, and you still get short tool life. A
few more pennies spent on a better alloy will save a lot in tooling.

Or have the parts cut on a LASER, we cut 304 all day long and the LASERs
don't wear out!

David

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Default Drilling 304 Stainless

Tim Wescott fired this volley in
:

This stuff breaks my regular old HSS drill bits, and my drill hand-
sharpening mojo is pretty spotty at 1/16".


Forgot, Tim...

Even the drilling must be done apace. If you dawdle or idle in the hole,
it will work-harden. You must drill smoothly through in one pass, or at
least _instantly_ retract the bit if you must stop before penetrating it.

Some coolant or cutting oil will help preserve your edges, too.

LLoyd


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Default Drilling 304 Stainless

On Thu, 30 Aug 2012 19:59:34 -0500, Tim Wescott
wrote:

I may have asked this before, but I'm slow:

I have some 304 sheet. I use it to make control-line model airplane
handles. Each handle needs to have about 20 1/16" or .050" holes drilled
in it, in a pair of tidy lines.

This stuff breaks my regular old HSS drill bits, and my drill hand-
sharpening mojo is pretty spotty at 1/16".

I'm using them in a drill press. The whole process feels weird -- it
feels like there's a skin on the metal which prevents the drill from
starting to cut unless I feed it fairly hard, but once broken through
doesn't cause much problem. Most of the time that I break a drill bit
it's because I'm feeding it "just a bit harder", then SPING -- I've
broken another bit.

Is there a better drill bit to use, or have I just doomed myself to
trouble? Is there a better flavor of _stainless_ to use? I understand
that 304 is difficult to work with, but it's what McMaster had in the
thickness I wanted; having experienced its joys, however, I'm ready to
consider something else.

I think my next step is to get a dozen 1/16" drill bits, but if there's
some magic material that'll help here, I'm listening.

Any reason not to use 6061T6 aluminum instead??? If you NEED to use
stainless, you will NEED a better drill bit. With stainless you need a
POSITIVE feed - never let the bit skate on the surface. I'd try a
good center punch - or use a "center drill" to make the starting
dimple, then follow through with the normal bit. Get one of those
that they show at tradeshows etc drilling through files and leaf
springs, and using them as milling cutters.
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Default Drilling 304 Stainless


Tim Wescott wrote:

I may have asked this before, but I'm slow:

I have some 304 sheet. I use it to make control-line model airplane
handles. Each handle needs to have about 20 1/16" or .050" holes drilled
in it, in a pair of tidy lines.

This stuff breaks my regular old HSS drill bits, and my drill hand-
sharpening mojo is pretty spotty at 1/16".

I'm using them in a drill press. The whole process feels weird -- it
feels like there's a skin on the metal which prevents the drill from
starting to cut unless I feed it fairly hard, but once broken through
doesn't cause much problem. Most of the time that I break a drill bit
it's because I'm feeding it "just a bit harder", then SPING -- I've
broken another bit.

Is there a better drill bit to use, or have I just doomed myself to
trouble? Is there a better flavor of _stainless_ to use? I understand
that 304 is difficult to work with, but it's what McMaster had in the
thickness I wanted; having experienced its joys, however, I'm ready to
consider something else.

I think my next step is to get a dozen 1/16" drill bits, but if there's
some magic material that'll help here, I'm listening.


I'm thinking very short carbide drills in the CNC mill for precise and
consistent feed rate and perhaps some appropriate coolant.
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Default Drilling 304 Stainless

304 stainless work hardens if you don't put enough pressure on the drill
bit. Also slow is much better than fast, a surface speed of about 50
ft. per minute. If you have a workhardened started hole if you
continue drilling the new or sharpened drill will get dull as it cuts
the workhardened metal. Once you get through the work hard metal,
resharpen or replace the drill or you will wind up with another work
hardened hole.
You could get a carbide drill that would work much better.

John

Tim Wescott wrote:
I may have asked this before, but I'm slow:

I have some 304 sheet. I use it to make control-line model airplane
handles. Each handle needs to have about 20 1/16" or .050" holes drilled
in it, in a pair of tidy lines.

This stuff breaks my regular old HSS drill bits, and my drill hand-
sharpening mojo is pretty spotty at 1/16".

I'm using them in a drill press. The whole process feels weird -- it
feels like there's a skin on the metal which prevents the drill from
starting to cut unless I feed it fairly hard, but once broken through
doesn't cause much problem. Most of the time that I break a drill bit
it's because I'm feeding it "just a bit harder", then SPING -- I've
broken another bit.

Is there a better drill bit to use, or have I just doomed myself to
trouble? Is there a better flavor of _stainless_ to use? I understand
that 304 is difficult to work with, but it's what McMaster had in the
thickness I wanted; having experienced its joys, however, I'm ready to
consider something else.

I think my next step is to get a dozen 1/16" drill bits, but if there's
some magic material that'll help here, I'm listening.


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Default Drilling 304 Stainless

wrote:
On Thu, 30 Aug 2012 19:59:34 -0500, Tim Wescott
wrote:

I may have asked this before, but I'm slow:

I have some 304 sheet. I use it to make control-line model airplane
handles. Each handle needs to have about 20 1/16" or .050" holes drilled
in it, in a pair of tidy lines.

This stuff breaks my regular old HSS drill bits, and my drill hand-
sharpening mojo is pretty spotty at 1/16".

I'm using them in a drill press. The whole process feels weird -- it
feels like there's a skin on the metal which prevents the drill from
starting to cut unless I feed it fairly hard, but once broken through
doesn't cause much problem. Most of the time that I break a drill bit
it's because I'm feeding it "just a bit harder", then SPING -- I've
broken another bit.

Is there a better drill bit to use, or have I just doomed myself to
trouble? Is there a better flavor of _stainless_ to use? I understand
that 304 is difficult to work with, but it's what McMaster had in the
thickness I wanted; having experienced its joys, however, I'm ready to
consider something else.

I think my next step is to get a dozen 1/16" drill bits, but if there's
some magic material that'll help here, I'm listening.

Any reason not to use 6061T6 aluminum instead??? If you NEED to use
stainless, you will NEED a better drill bit. With stainless you need a
POSITIVE feed - never let the bit skate on the surface. I'd try a
good center punch - or use a "center drill" to make the starting
dimple, then follow through with the normal bit. Get one of those
that they show at tradeshows etc drilling through files and leaf
springs, and using them as milling cutters.



303 stainless will machine and drill much better because of the sulfur
content of the metal. The bad part is that 303 doesn't weld well
because of the sulfur content.

John
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Default Drilling 304 Stainless

On Thu, 30 Aug 2012 19:59:34 -0500, Tim Wescott
wrote:

I may have asked this before, but I'm slow:

I have some 304 sheet. I use it to make control-line model airplane
handles. Each handle needs to have about 20 1/16" or .050" holes drilled
in it, in a pair of tidy lines.

This stuff breaks my regular old HSS drill bits, and my drill hand-
sharpening mojo is pretty spotty at 1/16".

I'm using them in a drill press. The whole process feels weird -- it
feels like there's a skin on the metal which prevents the drill from
starting to cut unless I feed it fairly hard, but once broken through
doesn't cause much problem. Most of the time that I break a drill bit
it's because I'm feeding it "just a bit harder", then SPING -- I've
broken another bit.

Is there a better drill bit to use, or have I just doomed myself to
trouble? Is there a better flavor of _stainless_ to use? I understand
that 304 is difficult to work with, but it's what McMaster had in the
thickness I wanted; having experienced its joys, however, I'm ready to
consider something else.

I think my next step is to get a dozen 1/16" drill bits, but if there's
some magic material that'll help here, I'm listening.


If you can live with 1/8" thick material, McMaster has 303 SS up to 2"
wide. Thin 304 sheet is cold rolled, and consequently work hardened,
making it much nastier to machine than hot rolled stock. 303 is a free
machining (relatively speaking) grade, and would be the best bet if
you can use an available size. But not recommended for welding.

--
Ned Simmons


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Default Drilling 304 Stainless

On Thu, 30 Aug 2012 21:50:56 -0400, clare wrote:

On Thu, 30 Aug 2012 19:59:34 -0500, Tim Wescott
wrote:

I may have asked this before, but I'm slow:

I have some 304 sheet. I use it to make control-line model airplane
handles. Each handle needs to have about 20 1/16" or .050" holes
drilled in it, in a pair of tidy lines.

This stuff breaks my regular old HSS drill bits, and my drill hand-
sharpening mojo is pretty spotty at 1/16".

I'm using them in a drill press. The whole process feels weird -- it
feels like there's a skin on the metal which prevents the drill from
starting to cut unless I feed it fairly hard, but once broken through
doesn't cause much problem. Most of the time that I break a drill bit
it's because I'm feeding it "just a bit harder", then SPING -- I've
broken another bit.

Is there a better drill bit to use, or have I just doomed myself to
trouble? Is there a better flavor of _stainless_ to use? I understand
that 304 is difficult to work with, but it's what McMaster had in the
thickness I wanted; having experienced its joys, however, I'm ready to
consider something else.

I think my next step is to get a dozen 1/16" drill bits, but if there's
some magic material that'll help here, I'm listening.

Any reason not to use 6061T6 aluminum instead??? If you NEED to use
stainless, you will NEED a better drill bit. With stainless you need a
POSITIVE feed - never let the bit skate on the surface. I'd try a good
center punch - or use a "center drill" to make the starting dimple, then
follow through with the normal bit. Get one of those that they show at
tradeshows etc drilling through files and leaf springs, and using them
as milling cutters.


Aluminum wears too quickly. The holes are for steel line clips, which
must bear the centrifugal force of the airplane at the same time that the
handle is being worked.

But it would make the job much easier.

--
Tim Wescott
Control system and signal processing consulting
www.wescottdesign.com
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Default Drilling 304 Stainless

On Thu, 30 Aug 2012 21:58:28 -0400, john wrote:

wrote:
On Thu, 30 Aug 2012 19:59:34 -0500, Tim Wescott
wrote:

I may have asked this before, but I'm slow:

I have some 304 sheet. I use it to make control-line model airplane
handles. Each handle needs to have about 20 1/16" or .050" holes
drilled in it, in a pair of tidy lines.

This stuff breaks my regular old HSS drill bits, and my drill hand-
sharpening mojo is pretty spotty at 1/16".

I'm using them in a drill press. The whole process feels weird -- it
feels like there's a skin on the metal which prevents the drill from
starting to cut unless I feed it fairly hard, but once broken through
doesn't cause much problem. Most of the time that I break a drill bit
it's because I'm feeding it "just a bit harder", then SPING -- I've
broken another bit.

Is there a better drill bit to use, or have I just doomed myself to
trouble? Is there a better flavor of _stainless_ to use? I
understand that 304 is difficult to work with, but it's what McMaster
had in the thickness I wanted; having experienced its joys, however,
I'm ready to consider something else.

I think my next step is to get a dozen 1/16" drill bits, but if
there's some magic material that'll help here, I'm listening.

Any reason not to use 6061T6 aluminum instead??? If you NEED to use
stainless, you will NEED a better drill bit. With stainless you need a
POSITIVE feed - never let the bit skate on the surface. I'd try a good
center punch - or use a "center drill" to make the starting dimple,
then follow through with the normal bit. Get one of those that they
show at tradeshows etc drilling through files and leaf springs, and
using them as milling cutters.



303 stainless will machine and drill much better because of the sulfur
content of the metal. The bad part is that 303 doesn't weld well
because of the sulfur content.


McMaster doesn't carry it, but I suppose that means I should just look
around.

--
Tim Wescott
Control system and signal processing consulting
www.wescottdesign.com
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Default Drilling 304 Stainless

On Thu, 30 Aug 2012 21:58:48 -0400, Ned Simmons wrote:

On Thu, 30 Aug 2012 19:59:34 -0500, Tim Wescott
wrote:

I may have asked this before, but I'm slow:

I have some 304 sheet. I use it to make control-line model airplane
handles. Each handle needs to have about 20 1/16" or .050" holes
drilled in it, in a pair of tidy lines.

This stuff breaks my regular old HSS drill bits, and my drill hand-
sharpening mojo is pretty spotty at 1/16".

I'm using them in a drill press. The whole process feels weird -- it
feels like there's a skin on the metal which prevents the drill from
starting to cut unless I feed it fairly hard, but once broken through
doesn't cause much problem. Most of the time that I break a drill bit
it's because I'm feeding it "just a bit harder", then SPING -- I've
broken another bit.

Is there a better drill bit to use, or have I just doomed myself to
trouble? Is there a better flavor of _stainless_ to use? I understand
that 304 is difficult to work with, but it's what McMaster had in the
thickness I wanted; having experienced its joys, however, I'm ready to
consider something else.

I think my next step is to get a dozen 1/16" drill bits, but if there's
some magic material that'll help here, I'm listening.


If you can live with 1/8" thick material, McMaster has 303 SS up to 2"
wide. Thin 304 sheet is cold rolled, and consequently work hardened,
making it much nastier to machine than hot rolled stock. 303 is a free
machining (relatively speaking) grade, and would be the best bet if you
can use an available size. But not recommended for welding.


Good thought, but 1/8 is much too thick.

Man, I'm really not trying to reject all advise here...

--
Tim Wescott
Control system and signal processing consulting
www.wescottdesign.com
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Default Drilling 304 Stainless

On Thu, 30 Aug 2012 20:22:29 -0500, David R. Birch wrote:

On 8/30/2012 7:59 PM, Tim Wescott wrote:
I may have asked this before, but I'm slow:

I have some 304 sheet. I use it to make control-line model airplane
handles. Each handle needs to have about 20 1/16" or .050" holes
drilled in it, in a pair of tidy lines.

This stuff breaks my regular old HSS drill bits, and my drill hand-
sharpening mojo is pretty spotty at 1/16".

I'm using them in a drill press. The whole process feels weird -- it
feels like there's a skin on the metal which prevents the drill from
starting to cut unless I feed it fairly hard, but once broken through
doesn't cause much problem. Most of the time that I break a drill bit
it's because I'm feeding it "just a bit harder", then SPING -- I've
broken another bit.

Is there a better drill bit to use, or have I just doomed myself to
trouble? Is there a better flavor of _stainless_ to use? I understand
that 304 is difficult to work with, but it's what McMaster had in the
thickness I wanted; having experienced its joys, however, I'm ready to
consider something else.

I think my next step is to get a dozen 1/16" drill bits, but if there's
some magic material that'll help here, I'm listening.


304 SS is junk stainless, but cheap. The reason it's so hard to cut is
an absence of sulphur in the alloy for lubrication. You have to get the
speed & feed just right to cut it, and you still get short tool life. A
few more pennies spent on a better alloy will save a lot in tooling.

Or have the parts cut on a LASER, we cut 304 all day long and the LASERs
don't wear out!


Kinda spendy for one-offs. I know a guy who laser cuts balsa -- maybe
I'll see what kind of price he'd give me for making a handful of the
metal parts, assuming he wants to and can.

--
Tim Wescott
Control system and signal processing consulting
www.wescottdesign.com
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Aluminum wears too quickly. The holes are for steel line clips, which
must bear the centrifugal force of the airplane at the same time that the
handle is being worked.

But it would make the job much easier.


Just a thought... could/would some sort of hardened
bushing/fairlead/lead-out work?

It would make the handle assembly lighter as well

Erik

PS, I also flew a lot of C/L as a kid it was the mid/late 60's...

Combat, rat, and even dabbled in a little jet speed.

The hot handle of those days was red plastic, with a piece of cable
threaded through it. The ends of the cable had eyes swaged in with
'Nicopress' like sleeves. Not sure of the name... EZ-Just or EZ-Adjust
comes to mind...


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Default Drilling 304 Stainless

On Thu, 30 Aug 2012 22:43:57 -0700, Erik wrote:

Aluminum wears too quickly. The holes are for steel line clips, which
must bear the centrifugal force of the airplane at the same time that
the handle is being worked.

But it would make the job much easier.


Just a thought... could/would some sort of hardened
bushing/fairlead/lead-out work?

It would make the handle assembly lighter as well

Erik

PS, I also flew a lot of C/L as a kid it was the mid/late 60's...

Combat, rat, and even dabbled in a little jet speed.

The hot handle of those days was red plastic, with a piece of cable
threaded through it. The ends of the cable had eyes swaged in with
'Nicopress' like sleeves. Not sure of the name... EZ-Just or EZ-Adjust
comes to mind...


EZ-Just. I have one.

The hot ticket for control line stunt is a hard-point handle of some
sort, with no heavy cable to soften the response by acting as a spring.
The handle design I'm using uses a line of holes to adjust spacing, and
different-sized clips at the handle to adjust the neutral point. It's
exceptionally simple -- except for drilling those damned holes.

--
Tim Wescott
Control system and signal processing consulting
www.wescottdesign.com
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"David R. Birch" wrote in message
...

304 SS is junk stainless, but cheap.


Blink! Blink!

Junk stainless?

I don't think so.

The reason it's so hard to cut is an absence of sulphur in the alloy for
lubrication. You have to get the speed & feed just right to cut it, and
you still get short tool life. A few more pennies spent on a better alloy
will save a lot in tooling.


While I'd agree that a change of alloy would be helpful, to imply that this
is an inferior alloy is nonsense. It's no such thing. It simply isn't
free machining, as you implied, which has no relationship to its quality.

A free machining grade of stainless, if anything, might be considered a
somewhat inferior alloy, as the presence of sulfur (or selenium) tends to
lower chemical resistance, although improving machining characteristics
immeasurably. I

If the article in question can be fashioned from bar stock, that would be my
choice---303 S (or Se) stainless. However, that grade is not available as
plate, as it does not lend itself to welding, so there is limited need in
that configuration.

Harold

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Default Drilling 304 Stainless

Tim Wescott fired this volley in
:

The holes are for steel line clips, which
must bear the centrifugal force of the airplane at the same time that
the handle is being worked.


So, line the holes with SS grommets/hollow rivets.

It would even "look cool", with the grommets indicating that someone had
done something about the wear issue.

Lloyd


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In article ,
Tim Wescott wrote:

I think my next step is to get a dozen 1/16" drill bits, but if there's
some magic material that'll help here, I'm listening.


How thick is the stuff you are drilling?

Stainless work-hardens in a flash - you can't be dainty with it.

Use screw machine bits. Minimize stick-out. You want rigidity - if you
could stick a 1/16th collet in the mill and use it as an overbuilt drill
press, with the absolute minimum stickout to drill your sheet, that
would be lovely. But you should be able to do it in a drill press if
it's not terribly sloppy, and you do what you can to minimize stickout,
such as buying screw-machine bits.

Heat-Resistant Cobalt Steel Short-Length Drill Bits
$1.48 - $1.26 for 12+ (McMaster)

Carbide can be good and bad - it's hard which helps with cutting, but
it's brittle so it's prone to break if there is any flex. Plus it costs
more than steel.

You might also want to dab a bit of lube on there.

If you have fairly thin sheet, McMaster does seem to have ONE "combined
drill and countersink" with a 1/16th drill-point part - that gives you
something extra-rigid right down to the top of a very short drill.
2915A72 - kinda spendy at $6.54, but you do get two ends.

Then you have things like...

Straight-Flute Carbide Short-Length Drill Bits for Hard Steel
($11.13)
Carbide Small-Diameter Drill Bits with 1/8" Shank
($4.51)

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On Aug 31, 12:06*am, Tim Wescott wrote:


Man, I'm really not trying to reject all advise here...

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Control system and signal processing consultingwww.wescottdesign.com


Carpenter Tech has some excellent literature on machining stainless.
I think you have to register to download it, but well worth the
effort.

I would also look for cutting lube made for stainless. There are some
unusual lubes for stainless including ones with iodine in them. Not
sure if any of them are especially good for machining stainless, but
Carpenter Tech should have the information.

Dan



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I would use carbide on my CNC mill, personally. CNC also helps with
consistently using the same feedrate.

i

On 2012-08-31, Ecnerwal wrote:
In article ,
Tim Wescott wrote:

I think my next step is to get a dozen 1/16" drill bits, but if there's
some magic material that'll help here, I'm listening.


How thick is the stuff you are drilling?

Stainless work-hardens in a flash - you can't be dainty with it.

Use screw machine bits. Minimize stick-out. You want rigidity - if you
could stick a 1/16th collet in the mill and use it as an overbuilt drill
press, with the absolute minimum stickout to drill your sheet, that
would be lovely. But you should be able to do it in a drill press if
it's not terribly sloppy, and you do what you can to minimize stickout,
such as buying screw-machine bits.

Heat-Resistant Cobalt Steel Short-Length Drill Bits
$1.48 - $1.26 for 12+ (McMaster)

Carbide can be good and bad - it's hard which helps with cutting, but
it's brittle so it's prone to break if there is any flex. Plus it costs
more than steel.

You might also want to dab a bit of lube on there.

If you have fairly thin sheet, McMaster does seem to have ONE "combined
drill and countersink" with a 1/16th drill-point part - that gives you
something extra-rigid right down to the top of a very short drill.
2915A72 - kinda spendy at $6.54, but you do get two ends.

Then you have things like...

Straight-Flute Carbide Short-Length Drill Bits for Hard Steel
($11.13)
Carbide Small-Diameter Drill Bits with 1/8" Shank
($4.51)

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On Fri, 31 Aug 2012 07:49:40 -0400, Ecnerwal
wrote:

In article ,
Tim Wescott wrote:

I think my next step is to get a dozen 1/16" drill bits, but if there's
some magic material that'll help here, I'm listening.


How thick is the stuff you are drilling?

Stainless work-hardens in a flash - you can't be dainty with it.

Use screw machine bits. Minimize stick-out. You want rigidity - if you
could stick a 1/16th collet in the mill and use it as an overbuilt drill
press, with the absolute minimum stickout to drill your sheet, that
would be lovely. But you should be able to do it in a drill press if
it's not terribly sloppy, and you do what you can to minimize stickout,
such as buying screw-machine bits.

Heat-Resistant Cobalt Steel Short-Length Drill Bits
$1.48 - $1.26 for 12+ (McMaster)


As above use screw machine length drills, cobalt, not just plain HSS.
Run at 2773 RPM this should be 45 SFM. I would use original Cool Tool
if I had it, you know the stuff that really worked and was banned by
the Feds. Find some cutting juice recommended for stainless.

Remove 333 to reply.
Randy
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In article ,
Tim Wescott wrote:

I may have asked this before, but I'm slow:

I have some 304 sheet. I use it to make control-line model airplane
handles. Each handle needs to have about 20 1/16" or .050" holes drilled
in it, in a pair of tidy lines.

This stuff breaks my regular old HSS drill bits, and my drill hand-
sharpening mojo is pretty spotty at 1/16".

I'm using them in a drill press. The whole process feels weird -- it
feels like there's a skin on the metal which prevents the drill from
starting to cut unless I feed it fairly hard, but once broken through
doesn't cause much problem. Most of the time that I break a drill bit
it's because I'm feeding it "just a bit harder", then SPING -- I've
broken another bit.

Is there a better drill bit to use, or have I just doomed myself to
trouble? Is there a better flavor of _stainless_ to use? I understand
that 304 is difficult to work with, but it's what McMaster had in the
thickness I wanted; having experienced its joys, however, I'm ready to
consider something else.

I think my next step is to get a dozen 1/16" drill bits, but if there's
some magic material that'll help here, I'm listening.


I've drilled lots of 304 sheet using cobalt HSS drill bits (gotta be new
and SHARP) in a drill press, or better a mill used to drill, lubricated
with black sulfur oil.

The trick is to set the drill press or mill to turn slow and powerful,
be very heavy handed while drilling, and be liberal with the black
sulfur oil.

Some drill presses cannot turn slow enough for the larger drill bits,
like Unibits to cut a 1/2" hole.

Joe Gwinn
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Default Drilling 304 Stainless

On Thu, 30 Aug 2012 19:59:34 -0500, Tim Wescott
wrote:

I may have asked this before, but I'm slow:

I have some 304 sheet. I use it to make control-line model airplane
handles. Each handle needs to have about 20 1/16" or .050" holes drilled
in it, in a pair of tidy lines.

This stuff breaks my regular old HSS drill bits, and my drill hand-
sharpening mojo is pretty spotty at 1/16".

I'm using them in a drill press. The whole process feels weird -- it
feels like there's a skin on the metal which prevents the drill from
starting to cut unless I feed it fairly hard, but once broken through
doesn't cause much problem. Most of the time that I break a drill bit
it's because I'm feeding it "just a bit harder", then SPING -- I've
broken another bit.

Is there a better drill bit to use, or have I just doomed myself to
trouble? Is there a better flavor of _stainless_ to use? I understand
that 304 is difficult to work with, but it's what McMaster had in the
thickness I wanted; having experienced its joys, however, I'm ready to
consider something else.

I think my next step is to get a dozen 1/16" drill bits, but if there's
some magic material that'll help here, I'm listening.

Greetings Tim,
In your situation I would use stub length cobalt split point drills.
The split point is important. Use a high sulfur cutting oil. Your
local hardware store probably sells some type of cutting oil made for
threading. The dark stuff is usually a high sulfur cutting oil. You
need to make sure there is constant pressure on the drill and that it
is always cutting. If you start the drill gingerly there is a good
chance that the 304 will work harden and then the pressure it takes to
get the drill to cut goes way up. So start drilling like you mean it.
Also, back up the sheet with another piece of metal. Aluminum is fine,
mild steel too. Even hard maple might be OK. You don't want the sheet
flexing away from the drill. This lowers the cutting pressure which
leads to work hardening. Drilling into mild steel might be the best
because it is close to 304 in hardness(but not nearly as tough!) and
this will help prevent a burr being pushed out of the 304 and into the
back up material. So you end up with cleaner holes and the dril is not
as likely to break as it exits the 304. Ideally the drill should be
spinning at about 2400 rpm. But this means you would need to feed the
drill fast through the part to make sure it is cutting the whole time.
Less than a second to go through 1/16 material. So maybe slower speed
with constant pressure right from the start will be best for your
situation with the drill press.
Eric
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wrote in message
news
On Thu, 30 Aug 2012 19:59:34 -0500, Tim Wescott
wrote:

I may have asked this before, but I'm slow:

I have some 304 sheet. I use it to make control-line model airplane
handles. Each handle needs to have about 20 1/16" or .050" holes drilled
in it, in a pair of tidy lines.

This stuff breaks my regular old HSS drill bits, and my drill hand-
sharpening mojo is pretty spotty at 1/16".

I'm using them in a drill press. The whole process feels weird -- it
feels like there's a skin on the metal which prevents the drill from
starting to cut unless I feed it fairly hard, but once broken through
doesn't cause much problem. Most of the time that I break a drill bit
it's because I'm feeding it "just a bit harder", then SPING -- I've
broken another bit.

Is there a better drill bit to use, or have I just doomed myself to
trouble? Is there a better flavor of _stainless_ to use? I understand
that 304 is difficult to work with, but it's what McMaster had in the
thickness I wanted; having experienced its joys, however, I'm ready to
consider something else.

I think my next step is to get a dozen 1/16" drill bits, but if there's
some magic material that'll help here, I'm listening.

Greetings Tim,
In your situation I would use stub length cobalt split point drills.
The split point is important. Use a high sulfur cutting oil. Your
local hardware store probably sells some type of cutting oil made for
threading. The dark stuff is usually a high sulfur cutting oil. You
need to make sure there is constant pressure on the drill and that it
is always cutting. If you start the drill gingerly there is a good
chance that the 304 will work harden and then the pressure it takes to
get the drill to cut goes way up. So start drilling like you mean it.
Also, back up the sheet with another piece of metal. Aluminum is fine,
mild steel too. Even hard maple might be OK. You don't want the sheet
flexing away from the drill. This lowers the cutting pressure which
leads to work hardening. Drilling into mild steel might be the best
because it is close to 304 in hardness(but not nearly as tough!) and
this will help prevent a burr being pushed out of the 304 and into the
back up material. So you end up with cleaner holes and the dril is not
as likely to break as it exits the 304. Ideally the drill should be
spinning at about 2400 rpm. But this means you would need to feed the
drill fast through the part to make sure it is cutting the whole time.
Less than a second to go through 1/16 material. So maybe slower speed
with constant pressure right from the start will be best for your
situation with the drill press.
Eric



Suggest maybe a carbide spade drill--although he''ll get a tubular exit
burr, the sheet won't lift up due to flute helix causing slippage etc as it
breaks through.

http://www.travers.com/images/Items/...20-805-024.jpg




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On Fri, 31 Aug 2012 06:09:17 -0500, Lloyd E. Sponenburgh wrote:

Tim Wescott fired this volley in
:

The holes are for steel line clips, which must bear the centrifugal
force of the airplane at the same time that the handle is being worked.


So, line the holes with SS grommets/hollow rivets.

It would even "look cool", with the grommets indicating that someone had
done something about the wear issue.


The holes need to be spaced 100 mils apart, and the hole in the grommet
couldn't be less than 50 mil, and 1/16 is better. So it'd need to be a
pretty teeny grommet.

Any suggestions where to find such?

--
My liberal friends think I'm a conservative kook.
My conservative friends think I'm a liberal kook.
Why am I not happy that they have found common ground?

Tim Wescott, Communications, Control, Circuits & Software
http://www.wescottdesign.com
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Tim Wescott wrote:
On Fri, 31 Aug 2012 06:09:17 -0500, Lloyd E. Sponenburgh wrote:

Tim Wescott fired this volley in
:

The holes are for steel line clips, which must bear the centrifugal
force of the airplane at the same time that the handle is being worked.


So, line the holes with SS grommets/hollow rivets.

It would even "look cool", with the grommets indicating that someone had
done something about the wear issue.


The holes need to be spaced 100 mils apart, and the hole in the grommet
couldn't be less than 50 mil, and 1/16 is better. So it'd need to be a
pretty teeny grommet.

Any suggestions where to find such?

Stainless POP rivets? Install rivet, pop, hit the back side with a
grinder to smooth them off.
If you want the back to look pretty use a cupped grinding point to dress
them.

Or use the rivet heads and a press to form the back. Could even spin the
back side down.

--
Steve W.
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On Fri, 31 Aug 2012 13:17:45 -0400, Steve W. wrote:

Tim Wescott wrote:
On Fri, 31 Aug 2012 06:09:17 -0500, Lloyd E. Sponenburgh wrote:

Tim Wescott fired this volley in
:

The holes are for steel line clips, which must bear the centrifugal
force of the airplane at the same time that the handle is being
worked.


So, line the holes with SS grommets/hollow rivets.

It would even "look cool", with the grommets indicating that someone
had done something about the wear issue.


The holes need to be spaced 100 mils apart, and the hole in the grommet
couldn't be less than 50 mil, and 1/16 is better. So it'd need to be a
pretty teeny grommet.

Any suggestions where to find such?

Stainless POP rivets? Install rivet, pop, hit the back side with a
grinder to smooth them off.
If you want the back to look pretty use a cupped grinding point to dress
them.

Or use the rivet heads and a press to form the back. Could even spin the
back side down.


With a 1/16" shank, and a head (and hole size) smaller than 1/10"?

--
My liberal friends think I'm a conservative kook.
My conservative friends think I'm a liberal kook.
Why am I not happy that they have found common ground?

Tim Wescott, Communications, Control, Circuits & Software
http://www.wescottdesign.com
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Default Drilling 304 Stainless

Tim Wescott wrote:

I may have asked this before, but I'm slow:

I have some 304 sheet. I use it to make control-line model airplane
handles. Each handle needs to have about 20 1/16" or .050" holes drilled
in it, in a pair of tidy lines.

This stuff breaks my regular old HSS drill bits, and my drill hand-
sharpening mojo is pretty spotty at 1/16".

Try some split-point cobalt drill bits. They are literally only a few cents
more when you buy them from MSC, KBC, etc. than the plain HSS bits.
They are much more capable of handling harder materials.

Jon
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Tim Wescott fired this volley in
:

The holes need to be spaced 100 mils apart, and the hole in the grommet
couldn't be less than 50 mil, and 1/16 is better. So it'd need to be a
pretty teeny grommet.


You can purchase all variety of gauges of stainless hypodermic tubing
(McMaster-Carr), and spin-rivet it.

LLoyd


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On Fri, 31 Aug 2012 16:28:33 -0500, Lloyd E. Sponenburgh wrote:

Tim Wescott fired this volley in
:

The holes need to be spaced 100 mils apart, and the hole in the grommet
couldn't be less than 50 mil, and 1/16 is better. So it'd need to be a
pretty teeny grommet.


You can purchase all variety of gauges of stainless hypodermic tubing
(McMaster-Carr), and spin-rivet it.


What's a spin rivet?

--
My liberal friends think I'm a conservative kook.
My conservative friends think I'm a liberal kook.
Why am I not happy that they have found common ground?

Tim Wescott, Communications, Control, Circuits & Software
http://www.wescottdesign.com
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Tim Wescott fired this volley in
news
What's a spin rivet?


It's a technique. Using a former with a conical nose and an annular groove
around the nose, the nose is inserted in the bore, and the former is spun,
forming the tubing into a flanged head.

LLoyd
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This would increase the number of operations per hole, but anyway you might
consider getting a small-diameter, say 1/8", spotting drill or countersink
with a 120-degree point. Set you depth stop carefully and spot it, then
switch to a 1/16" screw machine drill (shorter fluting and longer solid
shank) to complete the hole.

Tom

"Tim Wescott" wrote in message
...

I may have asked this before, but I'm slow:

I have some 304 sheet. I use it to make control-line model airplane
handles. Each handle needs to have about 20 1/16" or .050" holes drilled
in it, in a pair of tidy lines.

This stuff breaks my regular old HSS drill bits, and my drill hand-
sharpening mojo is pretty spotty at 1/16".

I'm using them in a drill press. The whole process feels weird -- it
feels like there's a skin on the metal which prevents the drill from
starting to cut unless I feed it fairly hard, but once broken through
doesn't cause much problem. Most of the time that I break a drill bit
it's because I'm feeding it "just a bit harder", then SPING -- I've
broken another bit.

Is there a better drill bit to use, or have I just doomed myself to
trouble? Is there a better flavor of _stainless_ to use? I understand
that 304 is difficult to work with, but it's what McMaster had in the
thickness I wanted; having experienced its joys, however, I'm ready to
consider something else.

I think my next step is to get a dozen 1/16" drill bits, but if there's
some magic material that'll help here, I'm listening.

--
My liberal friends think I'm a conservative kook.
My conservative friends think I'm a liberal kook.
Why am I not happy that they have found common ground?

Tim Wescott, Communications, Control, Circuits & Software
http://www.wescottdesign.com

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Tim Wescott wrote:
On Fri, 31 Aug 2012 13:17:45 -0400, Steve W. wrote:

Tim Wescott wrote:
On Fri, 31 Aug 2012 06:09:17 -0500, Lloyd E. Sponenburgh wrote:

Tim Wescott fired this volley in
:

The holes are for steel line clips, which must bear the centrifugal
force of the airplane at the same time that the handle is being
worked.


So, line the holes with SS grommets/hollow rivets.

It would even "look cool", with the grommets indicating that someone
had done something about the wear issue.
The holes need to be spaced 100 mils apart, and the hole in the grommet
couldn't be less than 50 mil, and 1/16 is better. So it'd need to be a
pretty teeny grommet.

Any suggestions where to find such?

Stainless POP rivets? Install rivet, pop, hit the back side with a
grinder to smooth them off.
If you want the back to look pretty use a cupped grinding point to dress
them.

Or use the rivet heads and a press to form the back. Could even spin the
back side down.


With a 1/16" shank, and a head (and hole size) smaller than 1/10"?


I've seen them used on R/C stuff before. Not sure where they get them
though. I don't use them since I have a press and just make my own from
tubing like Lloyd mentions. Actually real easy to do.

--
Steve W.
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On Thu, 30 Aug 2012 23:03:50 -0500, Tim Wescott
wrote:

On Thu, 30 Aug 2012 21:50:56 -0400, clare wrote:

On Thu, 30 Aug 2012 19:59:34 -0500, Tim Wescott
wrote:

I may have asked this before, but I'm slow:

I have some 304 sheet. I use it to make control-line model airplane
handles. Each handle needs to have about 20 1/16" or .050" holes
drilled in it, in a pair of tidy lines.

This stuff breaks my regular old HSS drill bits, and my drill hand-
sharpening mojo is pretty spotty at 1/16".

I'm using them in a drill press. The whole process feels weird -- it
feels like there's a skin on the metal which prevents the drill from
starting to cut unless I feed it fairly hard, but once broken through
doesn't cause much problem. Most of the time that I break a drill bit
it's because I'm feeding it "just a bit harder", then SPING -- I've
broken another bit.

Is there a better drill bit to use, or have I just doomed myself to
trouble? Is there a better flavor of _stainless_ to use? I understand
that 304 is difficult to work with, but it's what McMaster had in the
thickness I wanted; having experienced its joys, however, I'm ready to
consider something else.

I think my next step is to get a dozen 1/16" drill bits, but if there's
some magic material that'll help here, I'm listening.

Any reason not to use 6061T6 aluminum instead??? If you NEED to use
stainless, you will NEED a better drill bit. With stainless you need a
POSITIVE feed - never let the bit skate on the surface. I'd try a good
center punch - or use a "center drill" to make the starting dimple, then
follow through with the normal bit. Get one of those that they show at
tradeshows etc drilling through files and leaf springs, and using them
as milling cutters.


Aluminum wears too quickly. The holes are for steel line clips, which
must bear the centrifugal force of the airplane at the same time that the
handle is being worked.

But it would make the job much easier.

Make 6 in less time than it takes to make 1 in stainless, and throw
them away when they wear. 6061T6 is pretty darn tough stuff too.


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On Thu, 30 Aug 2012 23:06:07 -0500, Tim Wescott
wrote:

On Thu, 30 Aug 2012 21:58:48 -0400, Ned Simmons wrote:

On Thu, 30 Aug 2012 19:59:34 -0500, Tim Wescott
wrote:

I may have asked this before, but I'm slow:

I have some 304 sheet. I use it to make control-line model airplane
handles. Each handle needs to have about 20 1/16" or .050" holes
drilled in it, in a pair of tidy lines.

This stuff breaks my regular old HSS drill bits, and my drill hand-
sharpening mojo is pretty spotty at 1/16".

I'm using them in a drill press. The whole process feels weird -- it
feels like there's a skin on the metal which prevents the drill from
starting to cut unless I feed it fairly hard, but once broken through
doesn't cause much problem. Most of the time that I break a drill bit
it's because I'm feeding it "just a bit harder", then SPING -- I've
broken another bit.

Is there a better drill bit to use, or have I just doomed myself to
trouble? Is there a better flavor of _stainless_ to use? I understand
that 304 is difficult to work with, but it's what McMaster had in the
thickness I wanted; having experienced its joys, however, I'm ready to
consider something else.

I think my next step is to get a dozen 1/16" drill bits, but if there's
some magic material that'll help here, I'm listening.


If you can live with 1/8" thick material, McMaster has 303 SS up to 2"
wide. Thin 304 sheet is cold rolled, and consequently work hardened,
making it much nastier to machine than hot rolled stock. 303 is a free
machining (relatively speaking) grade, and would be the best bet if you
can use an available size. But not recommended for welding.


Good thought, but 1/8 is much too thick.

Man, I'm really not trying to reject all advise here...

Can you get the use of a turret punch???
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On 2012-08-31, Lloyd E. Sponenburgh lloydspinsidemindspring.com wrote:
Tim Wescott fired this volley in
:

Is there a better drill bit to use, or have I just doomed myself to
trouble? Is there a better flavor of _stainless_ to use? I understand
that 304 is difficult to work with, but it's what McMaster had in the
thickness I wanted; having experienced its joys, however, I'm ready to
consider something else.


Are you center-punching the holes before drilling?

If so, there IS a "skin" to break through... you've work-hardened the piece
where it's punched.

A better strategy is to use a really short bit, and just drill.


And, to prevent it walking, best is to get split-point drill
bits. (I might get by preference cobalt steel split point bits in screw
machine length, since you don't need the longer flute length of jobber's
length bits.

An alternative to the split points (or perhaps just something to
use in *addition* to the above) would be to put down a layer of masking
tape, which makes it easier to keep a bit from walking when it starts.

Good luck,
DoN.

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wrote in message
...
snip---
But it would make the job much easier.

Make 6 in less time than it takes to make 1 in stainless, and throw
them away when they wear. 6061T6 is pretty darn tough stuff too.


Make them from 6061-T6 aluminum, then have them *hard anodized*. Much
better at wear resistance than stainless.

Harold

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The web of the point of typical twist drills doesn't cut.. instead, it rubs
under pressure to displace the metal (all the way through the workpiece or
to the bottom of a blind hole).
That's exactly what needs to be avoided with work-hardening materials.

Split-point drills begin cutting as soon as contact is made, and continue
cutting until the drill is stopped/withdrawn.

Aside from carbide drills, I believe the best approach would be to use
quality split-point drills, as Phil recommended trying, with a good cutting
lubricant.. while following the "uninterrupted feed" method which is
critical when cutting work-hardening materials, IME.

If the holes need deburred after drilling, a small mounted stone in a
Dremel/rotary tool will be quick, although a larger drill or countersink
will also do the trick (even if just turned with fingers), just so the
turning stops when the pressure is released.

--
WB
..........


"Tim Wescott" wrote in message
...
I may have asked this before, but I'm slow:

I have some 304 sheet. I use it to make control-line model airplane
handles. Each handle needs to have about 20 1/16" or .050" holes drilled
in it, in a pair of tidy lines.

This stuff breaks my regular old HSS drill bits, and my drill hand-
sharpening mojo is pretty spotty at 1/16".

I'm using them in a drill press. The whole process feels weird -- it
feels like there's a skin on the metal which prevents the drill from
starting to cut unless I feed it fairly hard, but once broken through
doesn't cause much problem. Most of the time that I break a drill bit
it's because I'm feeding it "just a bit harder", then SPING -- I've
broken another bit.

Is there a better drill bit to use, or have I just doomed myself to
trouble? Is there a better flavor of _stainless_ to use? I understand
that 304 is difficult to work with, but it's what McMaster had in the
thickness I wanted; having experienced its joys, however, I'm ready to
consider something else.

I think my next step is to get a dozen 1/16" drill bits, but if there's
some magic material that'll help here, I'm listening.

--
My liberal friends think I'm a conservative kook.
My conservative friends think I'm a liberal kook.
Why am I not happy that they have found common ground?

Tim Wescott, Communications, Control, Circuits & Software
http://www.wescottdesign.com


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Posts: 539
Default Drilling 304 Stainless

Let's all give Wild Bill a round of applause, eih?
;)}
My filters left me 56 posts to look at and only
TWO
were on topic metalworking! Thanks Bill ! Good
advice
too..... I wonder how Tim worked it out?
I've been playing around making a couple of eulers
disks for the heck of it with various radius'. Got
one
at 14.5 " 16" and 20" radius so far. Made disks
with
various edges too to play with. Fun.....
philk

"Wild_Bill" wrote in
message
...
The web of the point of typical twist drills
doesn't cut.. instead, it rubs under pressure to
displace the metal (all the way through the
workpiece or to the bottom of a blind hole).
That's exactly what needs to be avoided with
work-hardening materials.

Split-point drills begin cutting as soon as
contact is made, and continue cutting until the
drill is stopped/withdrawn.

Aside from carbide drills, I believe the best
approach would be to use quality split-point
drills, as Phil recommended trying, with a good
cutting lubricant.. while following the
"uninterrupted feed" method which is critical
when cutting work-hardening materials, IME.

If the holes need deburred after drilling, a
small mounted stone in a Dremel/rotary tool will
be quick, although a larger drill or countersink
will also do the trick (even if just turned with
fingers), just so the turning stops when the
pressure is released.

--
WB
.........


"Tim Wescott" wrote in
message
...
I may have asked this before, but I'm slow:

I have some 304 sheet. I use it to make
control-line model airplane
handles. Each handle needs to have about 20
1/16" or .050" holes drilled
in it, in a pair of tidy lines.

This stuff breaks my regular old HSS drill
bits, and my drill hand-
sharpening mojo is pretty spotty at 1/16".

I'm using them in a drill press. The whole
process feels weird -- it
feels like there's a skin on the metal which
prevents the drill from
starting to cut unless I feed it fairly hard,
but once broken through
doesn't cause much problem. Most of the time
that I break a drill bit
it's because I'm feeding it "just a bit
harder", then SPING -- I've
broken another bit.

Is there a better drill bit to use, or have I
just doomed myself to
trouble? Is there a better flavor of
_stainless_ to use? I understand
that 304 is difficult to work with, but it's
what McMaster had in the
thickness I wanted; having experienced its
joys, however, I'm ready to
consider something else.

I think my next step is to get a dozen 1/16"
drill bits, but if there's
some magic material that'll help here, I'm
listening.

--
My liberal friends think I'm a conservative
kook.
My conservative friends think I'm a liberal
kook.
Why am I not happy that they have found common
ground?

Tim Wescott, Communications, Control, Circuits
& Software
http://www.wescottdesign.com





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