I need to make a pin .25" long by .096" diameter with a 0.109 by 0.117
head. It needs to be hard so I'll make it out of a 7/64 drill bit, the
size of the head.

What's a clever way to hold this in the lathe? it would be hard to
make soft jaws go down this small. I'm thinking some sort of
collapsible bushing that I'd drill.

Karl

Karl Townsend wrote:
I need to make a pin .25" long by .096" diameter with a 0.109 by 0.117
head. It needs to be hard so I'll make it out of a 7/64 drill bit, the
size of the head.

What's a clever way to hold this in the lathe? it would be hard to
make soft jaws go down this small. I'm thinking some sort of
collapsible bushing that I'd drill.

Karl



How about drilling a hole in a piece of round stock with the 7/64 bit.
Then gluing the bit in the hole. Mount the piece of round stock in the
chuck and go to work.

--
Steve W.

On 2/23/2012 9:54 PM, Karl Townsend wrote:
I need to make a pin .25" long by .096" diameter with a 0.109 by 0.117
head. It needs to be hard so I'll make it out of a 7/64 drill bit, the
size of the head.

What's a clever way to hold this in the lathe? it would be hard to
make soft jaws go down this small. I'm thinking some sort of
collapsible bushing that I'd drill.

Karl



A split sleeve - something like a collet?

Richard wrote:

On 2/23/2012 9:54 PM, Karl Townsend wrote:
I need to make a pin .25" long by .096" diameter with a 0.109 by 0.117
head. It needs to be hard so I'll make it out of a 7/64 drill bit, the
size of the head.

What's a clever way to hold this in the lathe? it would be hard to
make soft jaws go down this small. I'm thinking some sort of
collapsible bushing that I'd drill.

Karl



A split sleeve - something like a collet?


Like one from a Dremmel tool?


--
You can't have a sense of humor, if you have no sense.

On 2/23/2012 8:18 PM, Richard wrote:
On 2/23/2012 9:54 PM, Karl Townsend wrote:
I need to make a pin .25" long by .096" diameter with a 0.109 by 0.117
head. It needs to be hard so I'll make it out of a 7/64 drill bit, the
size of the head.

What's a clever way to hold this in the lathe? it would be hard to
make soft jaws go down this small. I'm thinking some sort of
collapsible bushing that I'd drill.

Karl



A split sleeve - something like a collet?
Once you get it made, how do you harden it without burning it up?

Paul

On 2012-02-24, Karl Townsend wrote:
I need to make a pin .25" long by .096" diameter with a 0.109 by 0.117
head. It needs to be hard so I'll make it out of a 7/64 drill bit, the
size of the head.

What's a clever way to hold this in the lathe? it would be hard to
make soft jaws go down this small. I'm thinking some sort of
collapsible bushing that I'd drill.

Can you use 5C collets? If so, consider getting an "emergency"
collet, soft, which can be drilled/bored to size.

Or -- if you have a small enough lathe with a Watchmaker's
spindle, you should be able to find a WW series collet of just the right
size. For the 0.109 (if that is the diameter), a #27 or #28 collet
(they are marked in tenths of mm). For the 0.117 (if *that* is the
diameter, you would need a #30 likely, or perhaps a #29. (It calculates
out as 2.9718mm FWIW.

The WW collets are one of my reasons for holding on to both my
Unimat SL-1000 (with the watchmaker's spindle), and the Taig (with a
similar but less versatile spindle).

Good Luck,
DoN.

--
Remove oil spill source from e-mail
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

Paul Drahn fired this volley in news:ji74af$glc$2
@dont-email.me:

Once you get it made, how do you harden it without burning it up?

Paul


Wrap it in stainless steel heat treating wrapping foil first. And start
the process in a carburizing atmosphere.

LLoyd

Wind some wire around it to build up the diameter.

On Thu, 23 Feb 2012 21:54:33 -0600, Karl Townsend
wrote:

I need to make a pin .25" long by .096" diameter with a 0.109 by 0.117
head. It needs to be hard so I'll make it out of a 7/64 drill bit, the
size of the head.

What's a clever way to hold this in the lathe? it would be hard to
make soft jaws go down this small. I'm thinking some sort of
collapsible bushing that I'd drill.

Karl




Regards,

Boris Mohar

Got Knock? - see:
Viatrack Printed Circuit Designs (among other things) http://www.viatrack.ca

void _-void-_ in the obvious place

On Feb 23, 7:54*pm, Karl Townsend
wrote:
I need to make a pin .25" long by .096" diameter with a 0.109 by 0.117
head. It needs to be hard so I'll make it out of a 7/64 drill bit, the
size of the head.

What's a clever way to hold this in the lathe? it would be hard to
make soft jaws go down this small. I'm thinking some sort of
collapsible bushing that I'd drill.

Karl

Seems simple for a smart guy like Karl so I must be missing something
but here goes anywar: I would make it like this

Chuck up a piece of 0.25 drill rod (O-1) in the late 3 jaw chuck with
1/2 inch extending out

Cut the diameter to 0.109 by 0.357 long

Cut down to 0.096 by 0.25 long

It is going to spring a little so use light cuts to finsh it off

Part it off

Heat treat by placing it on an SS plate and heat from the bottom

I made several pins this way with even smaller diameters

On Thu, 23 Feb 2012 21:54:33 -0600, Karl Townsend
wrote:

I need to make a pin .25" long by .096" diameter with a 0.109 by 0.117
head. It needs to be hard so I'll make it out of a 7/64 drill bit, the
size of the head.

What's a clever way to hold this in the lathe? it would be hard to
make soft jaws go down this small. I'm thinking some sort of
collapsible bushing that I'd drill.

Karl

What am I missing? Why not a 7/64 collet?

--
Ned Simmons

On Feb 23, 8:54*pm, Karl Townsend
wrote:
I need to make a pin .25" long by .096" diameter with a 0.109 by 0.117
head. It needs to be hard so I'll make it out of a 7/64 drill bit, the
size of the head.

What's a clever way to hold this in the lathe? it would be hard to
make soft jaws go down this small. I'm thinking some sort of
collapsible bushing that I'd drill.

Karl

They do make pin vises for such things, chuck it up in that, then
center it up in the 4 jaw. And drill shanks are soft and you'll have
a hard time hardening it if the bit is HSS. Go get a piece of drill
rod the right size, the good stuff comes with heat treatment
instructions so you can get the proper hardness. You could almost
chuck the thing in an electric drill and reduce the size with a file.
There's not that much to take off. Make two while you're at it.

Stan

"Karl Townsend" wrote in message
...
I need to make a pin .25" long by .096" diameter with a 0.109 by
0.117
head. It needs to be hard so I'll make it out of a 7/64 drill bit,
the
size of the head.

What's a clever way to hold this in the lathe? it would be hard to
make soft jaws go down this small. I'm thinking some sort of
collapsible bushing that I'd drill.

Karl

Stick it in a drill chuck. You could grab the drill chuck in the lathe
chuck or maybe fit the tailstock chuck to the spindle with a
live-center sleeve.

Jacobs ball-bearings chucks work pretty well on a lathe spindle. I
leave a 1/2" 33B on my 6" lathe and have a 58B on the indexer, and
made an adapter to fit it to the South Bend.
http://www.armurerieduroi.com/pages/...ck_jacobs.html
http://www.practicalmachinist.com/vb...img_6732-2.jpg

In one of their pamphlets SB says the chuck was meant for refinishing
automotive valves and shouldn't be used for heavy turning.

jsw

"Karl Townsend" wrote in message
...
I need to make a pin .25" long by .096" diameter with a 0.109 by
0.117
head. It needs to be hard so I'll make it out of a 7/64 drill bit,
the
size of the head.

What's a clever way to hold this in the lathe? it would be hard to
make soft jaws go down this small. I'm thinking some sort of
collapsible bushing that I'd drill.

Karl

You made me curious so I went down to check. 1/8" music wire in a 5C
collet cuts easily with HSS, ground to a sharp point to make a square
shoulder.

jsw

On Fri, 24 Feb 2012 06:36:53 -0800 (PST), toolbreaker
wrote:

On Feb 23, 7:54*pm, Karl Townsend
wrote:
I need to make a pin .25" long by .096" diameter with a 0.109 by 0.117
head. It needs to be hard so I'll make it out of a 7/64 drill bit, the
size of the head.

What's a clever way to hold this in the lathe? it would be hard to
make soft jaws go down this small. I'm thinking some sort of
collapsible bushing that I'd drill.

Karl

Seems simple for a smart guy like Karl so I must be missing something
but here goes anywar: I would make it like this

Chuck up a piece of 0.25 drill rod (O-1) in the late 3 jaw chuck with
1/2 inch extending out

Cut the diameter to 0.109 by 0.357 long

Cut down to 0.096 by 0.25 long

It is going to spring a little so use light cuts to finsh it off

Part it off

Heat treat by placing it on an SS plate and heat from the bottom

I made several pins this way with even smaller diameters




Doh! This is how I did it. Sometimes i have a brain fart.

I've got 2J collets for my 10EE but not many real small ones.

Karl

On 24 Feb 2012 05:31:07 GMT, "DoN. Nichols"
wrote:

On 2012-02-24, Karl Townsend wrote:
I need to make a pin .25" long by .096" diameter with a 0.109 by 0.117
head. It needs to be hard so I'll make it out of a 7/64 drill bit, the
size of the head.

What's a clever way to hold this in the lathe? it would be hard to
make soft jaws go down this small. I'm thinking some sort of
collapsible bushing that I'd drill.

Can you use 5C collets? If so, consider getting an "emergency"
collet, soft, which can be drilled/bored to size.

Or -- if you have a small enough lathe with a Watchmaker's
spindle, you should be able to find a WW series collet of just the right
size. For the 0.109 (if that is the diameter), a #27 or #28 collet
(they are marked in tenths of mm). For the 0.117 (if *that* is the
diameter, you would need a #30 likely, or perhaps a #29. (It calculates
out as 2.9718mm FWIW.

The WW collets are one of my reasons for holding on to both my
Unimat SL-1000 (with the watchmaker's spindle), and the Taig (with a
similar but less versatile spindle).

Good Luck,
DoN.
Mabee something like a pin vise?

On Fri, 24 Feb 2012 18:00:58 -0500, wrote:

On 24 Feb 2012 05:31:07 GMT, "DoN. Nichols"
wrote:

On 2012-02-24, Karl Townsend wrote:
I need to make a pin .25" long by .096" diameter with a 0.109 by 0.117
head. It needs to be hard so I'll make it out of a 7/64 drill bit, the
size of the head.

What's a clever way to hold this in the lathe? it would be hard to
make soft jaws go down this small. I'm thinking some sort of
collapsible bushing that I'd drill.

Can you use 5C collets? If so, consider getting an "emergency"
collet, soft, which can be drilled/bored to size.

Or -- if you have a small enough lathe with a Watchmaker's
spindle, you should be able to find a WW series collet of just the right
size. For the 0.109 (if that is the diameter), a #27 or #28 collet
(they are marked in tenths of mm). For the 0.117 (if *that* is the
diameter, you would need a #30 likely, or perhaps a #29. (It calculates
out as 2.9718mm FWIW.

The WW collets are one of my reasons for holding on to both my
Unimat SL-1000 (with the watchmaker's spindle), and the Taig (with a
similar but less versatile spindle).

Good Luck,
DoN.
Mabee something like a pin vise?

If this is a onesie job, and if there are some standard collets
available, the way I do these things is to wrap steel or copper wire
aound the shank until it fits in a standard collet. You can only use a
single layer, of course.

Otherwise, I turn a sub-collet from anything available and split it
down one side. I've tried splitting them part-way down, with two or
four slits, but the end result doesn't seem to be any better.

Someone mentioned that the shanks of drill bits are soft. That's quite
accurate. Also, they aren't any specific dimension. They're smaller
than the nominal diameter of the bit. Sometimes, they aren't very
round, either.

Oil-hardening drill rod is the ideal material. But you could also make
them from mustic wire. It's going to be quite hard, but it's
plain-carbon steel, so you can anneal it over a kitchen range or
(carefully) with a torch. Then it's easy to heat-treat, heating
quickly and quenching in oil (it's so small that there's no need for
water). Just don't soak it at heat or it will be brittle as hell, from
coarsening of the grain, and you'll de-carb the part. Then temper at
350 - 425 F in a kitchen oven, for an hour or so, to get maximum
strength.

--
Ed Huntress

On 2012-02-24, Paul Drahn wrote:
On 2/23/2012 8:18 PM, Richard wrote:
On 2/23/2012 9:54 PM, Karl Townsend wrote:
I need to make a pin .25" long by .096" diameter with a 0.109 by 0.117
head. It needs to be hard so I'll make it out of a 7/64 drill bit, the
size of the head.

Note that most drill bits have a soft shank and a HSS blade, so
the shank won't do much for you. I don't think that it has enough
carbon to harden well at all. (If you only need the surface hardened,
you can get some Kasenite or other case hardening pack material for heat
treating it.

Good Luck,
DoN.

--
Remove oil spill source from e-mail
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

On 25 Feb 2012 05:55:43 GMT, "DoN. Nichols"
wrote:

On 2012-02-24, Paul Drahn wrote:
On 2/23/2012 8:18 PM, Richard wrote:
On 2/23/2012 9:54 PM, Karl Townsend wrote:
I need to make a pin .25" long by .096" diameter with a 0.109 by 0.117
head. It needs to be hard so I'll make it out of a 7/64 drill bit, the
size of the head.

Note that most drill bits have a soft shank and a HSS blade, so
the shank won't do much for you. I don't think that it has enough
carbon to harden well at all. (If you only need the surface hardened,
you can get some Kasenite or other case hardening pack material for heat
treating it.

Don't case-harden HSS. The shank has plenty of carbon -- and chromium,
and probably molybdenum, to harden it up to over Rc 60.

However, it's not a good idea to do so. There are too many other
things going on with HSS alloys; you risk winding up with a weak part
unless you have good temperature control.

Note that a heat-and-quench hardening will harden HSS, but it won't
make it "high-speed." HSS requires a two-stage heat treatment in order
to develop red hardness, and the second stage is a
solution/precipitation hardening that is a real challenge in a home
shop. It can be done, but you have to know what alloy you're dealing
with and you have to know just what you're doing. You also need *very*
good temperature control.

Music wire or oil-hardening drill rod would be much preferred. They
can be easily and reliably hardened and tempered.

--
Ed Huntress





Good Luck,
DoN.

On 2012-02-25, Ed Huntress wrote:
On 25 Feb 2012 05:55:43 GMT, "DoN. Nichols"
wrote:

On 2012-02-24, Paul Drahn wrote:
On 2/23/2012 8:18 PM, Richard wrote:
On 2/23/2012 9:54 PM, Karl Townsend wrote:
I need to make a pin .25" long by .096" diameter with a 0.109 by 0.117
head. It needs to be hard so I'll make it out of a 7/64 drill bit, the
size of the head.

Note that most drill bits have a soft shank and a HSS blade, so
the shank won't do much for you. I don't think that it has enough
carbon to harden well at all. (If you only need the surface hardened,
you can get some Kasenite or other case hardening pack material for heat
treating it.

Don't case-harden HSS. The shank has plenty of carbon -- and chromium,
and probably molybdenum, to harden it up to over Rc 60.

Are you saying that the shank of a typical drill bit is also
HSS? I've always understood them to be mild steel welded to the HSS
which implements the flutes and other cutting surfaces.

I was assuming that if he used the shank, and had to harden it,
it would be mild steel, not HSS, so I was not advising case-hardening
HSS.

However, it's not a good idea to do so. There are too many other
things going on with HSS alloys; you risk winding up with a weak part
unless you have good temperature control.

And it is likely that *if* the shank is really HSS, you won't be
able to machine it anyway, unless with a toolpost grinder. :-)

Note that a heat-and-quench hardening will harden HSS, but it won't
make it "high-speed." HSS requires a two-stage heat treatment in order
to develop red hardness, and the second stage is a
solution/precipitation hardening that is a real challenge in a home
shop. It can be done, but you have to know what alloy you're dealing
with and you have to know just what you're doing. You also need *very*
good temperature control.

Not at all what I was advising.

Music wire or oil-hardening drill rod would be much preferred. They
can be easily and reliably hardened and tempered.

Agreed. Much better choices than old drill bit shanks.

Enjoy,
DoN.

--
Remove oil spill source from e-mail
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

On 26 Feb 2012 05:06:28 GMT, "DoN. Nichols"
wrote:

On 2012-02-25, Ed Huntress wrote:
On 25 Feb 2012 05:55:43 GMT, "DoN. Nichols"
wrote:

On 2012-02-24, Paul Drahn wrote:
On 2/23/2012 8:18 PM, Richard wrote:
On 2/23/2012 9:54 PM, Karl Townsend wrote:
I need to make a pin .25" long by .096" diameter with a 0.109 by 0.117
head. It needs to be hard so I'll make it out of a 7/64 drill bit, the
size of the head.

Note that most drill bits have a soft shank and a HSS blade, so
the shank won't do much for you. I don't think that it has enough
carbon to harden well at all. (If you only need the surface hardened,
you can get some Kasenite or other case hardening pack material for heat
treating it.

Don't case-harden HSS. The shank has plenty of carbon -- and chromium,
and probably molybdenum, to harden it up to over Rc 60.

Are you saying that the shank of a typical drill bit is also
HSS?

Yes.

I've always understood them to be mild steel welded to the HSS
which implements the flutes and other cutting surfaces.

I've never heard that. As far as I know, they just partially anneal
the shank, or maybe they don't quench the shank in the initial
heat-and-quench.


I was assuming that if he used the shank, and had to harden it,
it would be mild steel, not HSS, so I was not advising case-hardening
HSS.

However, it's not a good idea to do so. There are too many other
things going on with HSS alloys; you risk winding up with a weak part
unless you have good temperature control.

And it is likely that *if* the shank is really HSS, you won't be
able to machine it anyway, unless with a toolpost grinder. :-)

You can mill and turn annealed HSS. I've done it in my SB lathe, with
HSS lathe bits.

That is, assuming the shanks of HSS drill bits are HSS. g I'm pretty
sure they are, Don. I've never heard of them being welded. I would
think that would be an expensive way to make a dtill bit.

Before we leave this, we should point out that most grades of HSS have
*very* high carbon content -- 0.80% to 1.1%. That's up there in the
range of music wire and antique straight razors. You won't increase
hardenability by treating them with Kasenit. They already have all the
carbon they can use for hardening.

The problem with heat-treating HSS is that the alloy constituents that
form carbides (there are several) have to be heated just right or you
get variable results when they either 1) got back into solution or 2)
form free carbides. Without excellent temperature control and timing,
including temperature ramping and soaking, you get unknowable results,
with a strong possibility you will make the material brittle and weak.

So it's not a material to heat-and-quench with a torch, unless you're
willing to experiment.

--
Ed Huntress


Note that a heat-and-quench hardening will harden HSS, but it won't
make it "high-speed." HSS requires a two-stage heat treatment in order
to develop red hardness, and the second stage is a
solution/precipitation hardening that is a real challenge in a home
shop. It can be done, but you have to know what alloy you're dealing
with and you have to know just what you're doing. You also need *very*
good temperature control.

Not at all what I was advising.

Music wire or oil-hardening drill rod would be much preferred. They
can be easily and reliably hardened and tempered.

Agreed. Much better choices than old drill bit shanks.

Enjoy,
DoN.