Well, my delightfully high-quality Smithy lathe turned up a new defect
this week.

One of the T-bolts that hold the compound slide to it's base stripped.
Now, I could order a pair from Smithy, and get the same crap that they
sold me in the first place, or I could fabricate something and maybe have
a chance of it lasting for a while.

My challenge is that I want something that'll last, and I need to do it
without my lathe (boo hoo).

The bolts are M8x1 or so, maybe coarser thread. I'm thinking of going to
the farm store and getting some good old 'merican grade-8 5/16" bolts,
then cutting off the threaded parts for the T-bolts. Then I'll take some
stock about as thick as the heads on the old ones and I'll fabricate new
heads (or I'll use the old bolt heads). I'll thread them to match the
bolts, and I'll screw and braze the new heads onto the bolts.

This would be absolutely bullet-proof, except that the heat of the
brazing will ruin the temper of the bolt. I'm pretty sure that neither
peening the head onto the bolt, nor soft-soldering the head onto the
bolt, will have enough strength to hold together through one of those
"damn but this is tight" experiences one occasionally has with screws.

I'm also pretty sure that attempting to heat treat the bolts after
brazing won't get me a grade-8 bolt. I suspect that a 5/16" grade-8 bolt
isn't going to be made from the fanciest steel, so I can probably just
heat it up and chuck it into water, temper, and have something no worse
than without heat treating at all, but that's not exactly the most
scientific way to get 'er done.

Thoughts? Suggestions? It'd be fun to turn these out of drill rod,
except (a) I don't have any that big, and (b) I don't have a lathe right
now (boo hoo).

I'd kinda like to do this on the cheap, but if McMaster has just the
right thing (they don't) I'd at least like to know so I can feel virtuous
about the money I'm saving.

--
www.wescottdesign.com

The bolts are M8x1 or so, maybe coarser thread. I'm thinking of going to
the farm store and getting some good old 'merican grade-8 5/16" bolts,
then cutting off the threaded parts for the T-bolts. Then I'll take some
stock about as thick as the heads on the old ones and I'll fabricate new
heads (or I'll use the old bolt heads). I'll thread them to match the
bolts, and I'll screw and braze the new heads onto the bolts.

Do this, but don't quite finish with the tap. Put two nuts together really
tight on your all thread stock. Use a wrench to force the allthread into the
partially threaded head. Remove nuts.

Karl

On Tue, 29 Dec 2009 00:31:48 -0600, Tim Wescott wrote:


Thoughts? Suggestions? It'd be fun to turn these out of drill rod,
except (a) I don't have any that big, and (b) I don't have a lathe right
now (boo hoo).

These are not precision items.

Get a big enough bolt as stock and get to work - hacksaw, file, die.

"Tim Wescott" wrote in message
...
Well, my delightfully high-quality Smithy lathe turned up a new defect
this week.

One of the T-bolts that hold the compound slide to it's base stripped.
Now, I could order a pair from Smithy, and get the same crap that they
sold me in the first place, or I could fabricate something and maybe have
a chance of it lasting for a while.

My challenge is that I want something that'll last, and I need to do it
without my lathe (boo hoo).

The bolts are M8x1 or so, maybe coarser thread. I'm thinking of going to
the farm store and getting some good old 'merican grade-8 5/16" bolts,
then cutting off the threaded parts for the T-bolts. Then I'll take some
stock about as thick as the heads on the old ones and I'll fabricate new
heads (or I'll use the old bolt heads). I'll thread them to match the
bolts, and I'll screw and braze the new heads onto the bolts.

This would be absolutely bullet-proof, except that the heat of the
brazing will ruin the temper of the bolt. I'm pretty sure that neither
peening the head onto the bolt, nor soft-soldering the head onto the
bolt, will have enough strength to hold together through one of those
"damn but this is tight" experiences one occasionally has with screws.

I'm also pretty sure that attempting to heat treat the bolts after
brazing won't get me a grade-8 bolt. I suspect that a 5/16" grade-8 bolt
isn't going to be made from the fanciest steel, so I can probably just
heat it up and chuck it into water, temper, and have something no worse
than without heat treating at all, but that's not exactly the most
scientific way to get 'er done.

Thoughts? Suggestions? It'd be fun to turn these out of drill rod,
except (a) I don't have any that big, and (b) I don't have a lathe right
now (boo hoo).

I'd kinda like to do this on the cheap, but if McMaster has just the
right thing (they don't) I'd at least like to know so I can feel virtuous
about the money I'm saving.

--
www.wescottdesign.com

why don't you just buy a grade 8 teebolt? See:
http://www.use-enco.com/CGI/INPDFF?P...MITEM=319-8605

These come pre heat treated and in various lengths.

--

__
Roger Shoaf

Important factors in selecting a mate:
1] Depth of gene pool
2] Position on the food chain.

"Tim Wescott" wrote in message
...
Well, my delightfully high-quality Smithy lathe turned up a new defect
this week.

One of the T-bolts that hold the compound slide to it's base stripped.
Now, I could order a pair from Smithy, and get the same crap that they
sold me in the first place, or I could fabricate something and maybe have
a chance of it lasting for a while.

My challenge is that I want something that'll last, and I need to do it
without my lathe (boo hoo).

The bolts are M8x1 or so, maybe coarser thread. I'm thinking of going to
the farm store and getting some good old 'merican grade-8 5/16" bolts,
then cutting off the threaded parts for the T-bolts. Then I'll take some
stock about as thick as the heads on the old ones and I'll fabricate new
heads (or I'll use the old bolt heads). I'll thread them to match the
bolts, and I'll screw and braze the new heads onto the bolts.

This would be absolutely bullet-proof, except that the heat of the
brazing will ruin the temper of the bolt. I'm pretty sure that neither
peening the head onto the bolt, nor soft-soldering the head onto the
bolt, will have enough strength to hold together through one of those
"damn but this is tight" experiences one occasionally has with screws.

I'm also pretty sure that attempting to heat treat the bolts after
brazing won't get me a grade-8 bolt. I suspect that a 5/16" grade-8 bolt
isn't going to be made from the fanciest steel, so I can probably just
heat it up and chuck it into water, temper, and have something no worse
than without heat treating at all, but that's not exactly the most
scientific way to get 'er done.

Thoughts? Suggestions? It'd be fun to turn these out of drill rod,
except (a) I don't have any that big, and (b) I don't have a lathe right
now (boo hoo).

I'd kinda like to do this on the cheap, but if McMaster has just the
right thing (they don't) I'd at least like to know so I can feel virtuous
about the money I'm saving.

--
www.wescottdesign.com

Sorry,

I meant to say: Why not silver solder the bolt into the base. The temp won't be high enough to
affect temper.

Bob Swinney
"Robert Swinney" wrote in message
...

"Tim Wescott" wrote in message
...
Well, my delightfully high-quality Smithy lathe turned up a new defect
this week.

One of the T-bolts that hold the compound slide to it's base stripped.
Now, I could order a pair from Smithy, and get the same crap that they
sold me in the first place, or I could fabricate something and maybe have
a chance of it lasting for a while.

My challenge is that I want something that'll last, and I need to do it
without my lathe (boo hoo).

The bolts are M8x1 or so, maybe coarser thread. I'm thinking of going to
the farm store and getting some good old 'merican grade-8 5/16" bolts,
then cutting off the threaded parts for the T-bolts. Then I'll take some
stock about as thick as the heads on the old ones and I'll fabricate new
heads (or I'll use the old bolt heads). I'll thread them to match the
bolts, and I'll screw and braze the new heads onto the bolts.

This would be absolutely bullet-proof, except that the heat of the
brazing will ruin the temper of the bolt. I'm pretty sure that neither
peening the head onto the bolt, nor soft-soldering the head onto the
bolt, will have enough strength to hold together through one of those
"damn but this is tight" experiences one occasionally has with screws.

I'm also pretty sure that attempting to heat treat the bolts after
brazing won't get me a grade-8 bolt. I suspect that a 5/16" grade-8 bolt
isn't going to be made from the fanciest steel, so I can probably just
heat it up and chuck it into water, temper, and have something no worse
than without heat treating at all, but that's not exactly the most
scientific way to get 'er done.

Thoughts? Suggestions? It'd be fun to turn these out of drill rod,
except (a) I don't have any that big, and (b) I don't have a lathe right
now (boo hoo).

I'd kinda like to do this on the cheap, but if McMaster has just the
right thing (they don't) I'd at least like to know so I can feel virtuous
about the money I'm saving.

--
www.wescottdesign.com

On Tue, 29 Dec 2009 10:36:19 -0600, "Robert Swinney"
wrote:

Sorry,

I meant to say: Why not silver solder the bolt into the base. The temp won't be high enough to
affect temper.

Silver-brazing temperature will definitely draw temper and probably
anneal.

Don sez: "Silver-brazing temperature will definitely draw temper and probably
anneal."

Note use of word "probably" denoting doubt as to whether annealing would take place or not. If you
worry about such things, just quench the whole kit-n-kaboodle immediately after silver-brazing.
Careful, you don't use those bolts on any NASA projects.

Bob Swinney
"Don Foreman" wrote in message
...
On Tue, 29 Dec 2009 10:36:19 -0600, "Robert Swinney"
wrote:

Sorry,

I meant to say: Why not silver solder the bolt into the base. The temp won't be high enough to
affect temper.

On Dec 29, 1:31*am, Tim Wescott wrote:
...
My challenge is that I want something that'll last, and I need to do it
without my lathe (boo hoo)....

I'd make temporary tee bolts out of carriage bolts with washers
pounded onto the square, then use the now-functional lathe to make
better permanent ones.

jsw

On Dec 29, 12:31*am, Tim Wescott wrote:
Well, my delightfully high-quality Smithy lathe turned up a new defect
this week.

One of the T-bolts that hold the compound slide to it's base stripped. *
Now, I could order a pair from Smithy, and get the same crap that they
sold me in the first place, or I could fabricate something and maybe have
a chance of it lasting for a while.

My challenge is that I want something that'll last, and I need to do it
without my lathe (boo hoo).

The bolts are M8x1 or so, maybe coarser thread. *I'm thinking of going to
the farm store and getting some good old 'merican grade-8 5/16" bolts,
then cutting off the threaded parts for the T-bolts. *Then I'll take some
stock about as thick as the heads on the old ones and I'll fabricate new
heads (or I'll use the old bolt heads). *I'll thread them to match the
bolts, and I'll screw and braze the new heads onto the bolts.

This would be absolutely bullet-proof, except that the heat of the
brazing will ruin the temper of the bolt. *I'm pretty sure that neither
peening the head onto the bolt, nor soft-soldering the head onto the
bolt, will have enough strength to hold together through one of those
"damn but this is tight" experiences one occasionally has with screws.

I'm also pretty sure that attempting to heat treat the bolts after
brazing won't get me a grade-8 bolt. *I suspect that a 5/16" grade-8 bolt
isn't going to be made from the fanciest steel, so I can probably just
heat it up and chuck it into water, temper, and have something no worse
than without heat treating at all, but that's not exactly the most
scientific way to get 'er done.

Thoughts? *Suggestions? *It'd be fun to turn these out of drill rod,
except (a) I don't have any that big, and (b) I don't have a lathe right
now (boo hoo).

I'd kinda like to do this on the cheap, but if McMaster has just the
right thing (they don't) I'd at least like to know so I can feel virtuous
about the money I'm saving.

--www.wescottdesign.com

If you want to do it on the cheap, then I would find some proper
square head bolts and file them down to fit the slot in the tool
rest. You’d probably have to re-thread them too, unless you can find
some fully threaded ones.

Similarly you could shape some square machine nuts to work if you can
find some suitable ones.

I think that t-slot bolts or tee slot nuts from McMaster Carr would
also work well:
http://www.mcmaster.com/#machine-tab...t-nuts/=557vhk
http://www.mcmaster.com/#t-slot-bolts/=557w3u

On Tue, 29 Dec 2009 09:13:55 -0800, Jim Wilkins wrote:

On Dec 29, 1:31Â*am, Tim Wescott wrote:
...
My challenge is that I want something that'll last, and I need to do it
without my lathe (boo hoo)....

I'd make temporary tee bolts out of carriage bolts with washers pounded
onto the square, then use the now-functional lathe to make better
permanent ones.

jsw


Y'know, the T-bolt itself has a round head with flats; I think a 5/16"
carriage bolt may work with just a bit of grinding and no washer -- and
I've got some pretty classy ones left over from a high-falutin swing set
we bought for the kids; even if they're not grade 8 they're definitely a
cut above the usual hardware store crap. If they don't last any better
than what came with the lathe that'll still be enough time for me to
build something up at my leisure.

I think I'll use them if they work, then start looking for a deal on some
seriously hardenable steel -- this sounds like a good project to start
learning basic heat treating.

--
www.wescottdesign.com

On Dec 28, 11:31*pm, Tim Wescott wrote:
Well, my delightfully high-quality Smithy lathe turned up a new defect
this week.

One of the T-bolts that hold the compound slide to it's base stripped. *
Now, I could order a pair from Smithy, and get the same crap that they
sold me in the first place, or I could fabricate something and maybe have
a chance of it lasting for a while.

My challenge is that I want something that'll last, and I need to do it
without my lathe (boo hoo).

The bolts are M8x1 or so, maybe coarser thread. *I'm thinking of going to
the farm store and getting some good old 'merican grade-8 5/16" bolts,
then cutting off the threaded parts for the T-bolts. *Then I'll take some
stock about as thick as the heads on the old ones and I'll fabricate new
heads (or I'll use the old bolt heads). *I'll thread them to match the
bolts, and I'll screw and braze the new heads onto the bolts.

This would be absolutely bullet-proof, except that the heat of the
brazing will ruin the temper of the bolt. *I'm pretty sure that neither
peening the head onto the bolt, nor soft-soldering the head onto the
bolt, will have enough strength to hold together through one of those
"damn but this is tight" experiences one occasionally has with screws.

I'm also pretty sure that attempting to heat treat the bolts after
brazing won't get me a grade-8 bolt. *I suspect that a 5/16" grade-8 bolt
isn't going to be made from the fanciest steel, so I can probably just
heat it up and chuck it into water, temper, and have something no worse
than without heat treating at all, but that's not exactly the most
scientific way to get 'er done.

Thoughts? *Suggestions? *It'd be fun to turn these out of drill rod,
except (a) I don't have any that big, and (b) I don't have a lathe right
now (boo hoo).

I'd kinda like to do this on the cheap, but if McMaster has just the
right thing (they don't) I'd at least like to know so I can feel virtuous
about the money I'm saving.

--www.wescottdesign.com

Why not make t-nuts instead? Whack a suitable strip of steel to
width, file to fit, drill and tap holes and use the bolts of your
choice. Or studs. Bugger the last couple of threads on the bottom so
they don't bust the slot flanges off. Seems to me I bought a similar
t-slot clamping kit from Enco or the like for about $20 with all the
studs you'd ever need, but your slots may not be standard.

Stan

On Tue, 29 Dec 2009 10:33:25 -0800, stans4 wrote:

On Dec 28, 11:31Â*pm, Tim Wescott wrote:
Well, my delightfully high-quality Smithy lathe turned up a new defect
this week.

One of the T-bolts that hold the compound slide to it's base stripped.
Now, I could order a pair from Smithy, and get the same crap that they
sold me in the first place, or I could fabricate something and maybe
have a chance of it lasting for a while.

My challenge is that I want something that'll last, and I need to do it
without my lathe (boo hoo).

The bolts are M8x1 or so, maybe coarser thread. Â*I'm thinking of going
to the farm store and getting some good old 'merican grade-8 5/16"
bolts, then cutting off the threaded parts for the T-bolts. Â*Then I'll
take some stock about as thick as the heads on the old ones and I'll
fabricate new heads (or I'll use the old bolt heads). Â*I'll thread them
to match the bolts, and I'll screw and braze the new heads onto the
bolts.

This would be absolutely bullet-proof, except that the heat of the
brazing will ruin the temper of the bolt. Â*I'm pretty sure that neither
peening the head onto the bolt, nor soft-soldering the head onto the
bolt, will have enough strength to hold together through one of those
"damn but this is tight" experiences one occasionally has with screws.

I'm also pretty sure that attempting to heat treat the bolts after
brazing won't get me a grade-8 bolt. Â*I suspect that a 5/16" grade-8
bolt isn't going to be made from the fanciest steel, so I can probably
just heat it up and chuck it into water, temper, and have something no
worse than without heat treating at all, but that's not exactly the
most scientific way to get 'er done.

Thoughts? Â*Suggestions? Â*It'd be fun to turn these out of drill rod,
except (a) I don't have any that big, and (b) I don't have a lathe
right now (boo hoo).

I'd kinda like to do this on the cheap, but if McMaster has just the
right thing (they don't) I'd at least like to know so I can feel
virtuous about the money I'm saving.

--www.wescottdesign.com

Why not make t-nuts instead? Whack a suitable strip of steel to width,
file to fit, drill and tap holes and use the bolts of your choice. Or
studs. Bugger the last couple of threads on the bottom so they don't
bust the slot flanges off. Seems to me I bought a similar t-slot
clamping kit from Enco or the like for about $20 with all the studs
you'd ever need, but your slots may not be standard.

My slots are way not standard. I _may_ be able to do the T-nut thing if
I go fully custom, but I may not have enough clearance for the bolt to
tighten satisfactorily.

Good idea, though -- I will investigate.

--
www.wescottdesign.com

On Tue, 29 Dec 2009 00:31:48 -0600, Tim Wescott wrote:

Well, my delightfully high-quality Smithy lathe turned up a new defect
this week.

One of the T-bolts that hold the compound slide to it's base stripped.
Now, I could order a pair from Smithy, and get the same crap that they
sold me in the first place, or I could fabricate something and maybe
have a chance of it lasting for a while.

My challenge is that I want something that'll last, and I need to do it
without my lathe (boo hoo).

The bolts are M8x1 or so, maybe coarser thread. I'm thinking of going
to the farm store and getting some good old 'merican grade-8 5/16"
bolts, then cutting off the threaded parts for the T-bolts. Then I'll
take some stock about as thick as the heads on the old ones and I'll
fabricate new heads (or I'll use the old bolt heads). I'll thread them
to match the bolts, and I'll screw and braze the new heads onto the
bolts.

This would be absolutely bullet-proof, except that the heat of the
brazing will ruin the temper of the bolt. I'm pretty sure that neither
peening the head onto the bolt, nor soft-soldering the head onto the
bolt, will have enough strength to hold together through one of those
"damn but this is tight" experiences one occasionally has with screws.

I'm also pretty sure that attempting to heat treat the bolts after
brazing won't get me a grade-8 bolt. I suspect that a 5/16" grade-8
bolt isn't going to be made from the fanciest steel, so I can probably
just heat it up and chuck it into water, temper, and have something no
worse than without heat treating at all, but that's not exactly the most
scientific way to get 'er done.

Thoughts? Suggestions? It'd be fun to turn these out of drill rod,
except (a) I don't have any that big, and (b) I don't have a lathe right
now (boo hoo).

I'd kinda like to do this on the cheap, but if McMaster has just the
right thing (they don't) I'd at least like to know so I can feel
virtuous about the money I'm saving.

Update: the 5/16" carriage bolt seems to work. I bashed flats into the
head with a hammer (in an attempt to get a bit of depth) and filed the
resulting lips flat. The original bolt has a 710 mil diameter circular
head with flats that are about 550 mils across; the carriage bolt is
smaller around than this, but I made it's flats to fit closer to the
channel in the cross-slide base.

So if anything happens now it'll be the somewhat undersized head of the
carriage bolt rounding off in the channel. Or the other original bolt
going south...

I'm going to use it, and Real Soon Now I'll either make some bolts per
the original, or I'll make some T-nuts out of 3/4" stock with appropriate
flats milled/filed/ground/hacked in, for use with regular cap screws. If
I get my hands on something I can harden I may even use that.

--
www.wescottdesign.com

Tim Wescott wrote:
On Tue, 29 Dec 2009 00:31:48 -0600, Tim Wescott wrote:


Well, my delightfully high-quality Smithy lathe turned up a new defect
this week.

One of the T-bolts that hold the compound slide to it's base stripped.
Now, I could order a pair from Smithy, and get the same crap that they
sold me in the first place, or I could fabricate something and maybe
have a chance of it lasting for a while.

My challenge is that I want something that'll last, and I need to do it
without my lathe (boo hoo).

The bolts are M8x1 or so, maybe coarser thread. I'm thinking of going
to the farm store and getting some good old 'merican grade-8 5/16"
bolts, then cutting off the threaded parts for the T-bolts. Then I'll
take some stock about as thick as the heads on the old ones and I'll
fabricate new heads (or I'll use the old bolt heads). I'll thread them
to match the bolts, and I'll screw and braze the new heads onto the
bolts.

This would be absolutely bullet-proof, except that the heat of the
brazing will ruin the temper of the bolt. I'm pretty sure that neither
peening the head onto the bolt, nor soft-soldering the head onto the
bolt, will have enough strength to hold together through one of those
"damn but this is tight" experiences one occasionally has with screws.

I'm also pretty sure that attempting to heat treat the bolts after
brazing won't get me a grade-8 bolt. I suspect that a 5/16" grade-8
bolt isn't going to be made from the fanciest steel, so I can probably
just heat it up and chuck it into water, temper, and have something no
worse than without heat treating at all, but that's not exactly the most
scientific way to get 'er done.

Thoughts? Suggestions? It'd be fun to turn these out of drill rod,
except (a) I don't have any that big, and (b) I don't have a lathe right
now (boo hoo).

I'd kinda like to do this on the cheap, but if McMaster has just the
right thing (they don't) I'd at least like to know so I can feel
virtuous about the money I'm saving.


Update: the 5/16" carriage bolt seems to work. I bashed flats into the
head with a hammer (in an attempt to get a bit of depth) and filed the
resulting lips flat. The original bolt has a 710 mil diameter circular
head with flats that are about 550 mils across; the carriage bolt is
smaller around than this, but I made it's flats to fit closer to the
channel in the cross-slide base.

So if anything happens now it'll be the somewhat undersized head of the
carriage bolt rounding off in the channel. Or the other original bolt
going south...

I'm going to use it, and Real Soon Now I'll either make some bolts per
the original, or I'll make some T-nuts out of 3/4" stock with appropriate
flats milled/filed/ground/hacked in, for use with regular cap screws. If
I get my hands on something I can harden I may even use that.


Maybe try and determine what T slot standard your lathe uses, you may be
able to buy the T nuts more cheaply and they will likely be case
hardened. I had a look at this recently as I made a T slot table for the
cross slide of my Harrison M300 and looked at the various T slot sizes I
had, the BP set was predominant but the size used on a 10" Vertex rotary
table won out at 7/16" T slot as far as I could tell. IIRC there are old
and new ISO standards with differing dimensions and the inch size T slot
standard. For the Vertex table that I have I made T nuts to suit the
slots and to suit the 1/2" Whitworth clamping kit even though the T
slots appear to be 7/16" spec.

"David Billington" wrote in message
...

Maybe try and determine what T slot standard your lathe uses, you may be
able to buy the T nuts more cheaply and they will likely be case
hardened. I had a look at this recently as I made a T slot table for the
cross slide of my Harrison M300 and looked at the various T slot sizes I
had, the BP set was predominant but the size used on a 10" Vertex rotary
table won out at 7/16" T slot as far as I could tell. IIRC there are old
and new ISO standards with differing dimensions and the inch size T slot
standard. For the Vertex table that I have I made T nuts to suit the
slots and to suit the 1/2" Whitworth clamping kit even though the T
slots appear to be 7/16" spec.

I agree Enco sells Tee nuts down to 1/4 20 already heat treated.

On Tue, 29 Dec 2009 23:47:23 +0000, David Billington wrote:

Tim Wescott wrote:
On Tue, 29 Dec 2009 00:31:48 -0600, Tim Wescott wrote:


Well, my delightfully high-quality Smithy lathe turned up a new defect
this week.

One of the T-bolts that hold the compound slide to it's base stripped.
Now, I could order a pair from Smithy, and get the same crap that they
sold me in the first place, or I could fabricate something and maybe
have a chance of it lasting for a while.

My challenge is that I want something that'll last, and I need to do
it without my lathe (boo hoo).

The bolts are M8x1 or so, maybe coarser thread. I'm thinking of going
to the farm store and getting some good old 'merican grade-8 5/16"
bolts, then cutting off the threaded parts for the T-bolts. Then I'll
take some stock about as thick as the heads on the old ones and I'll
fabricate new heads (or I'll use the old bolt heads). I'll thread
them to match the bolts, and I'll screw and braze the new heads onto
the bolts.

This would be absolutely bullet-proof, except that the heat of the
brazing will ruin the temper of the bolt. I'm pretty sure that
neither peening the head onto the bolt, nor soft-soldering the head
onto the bolt, will have enough strength to hold together through one
of those "damn but this is tight" experiences one occasionally has
with screws.

I'm also pretty sure that attempting to heat treat the bolts after
brazing won't get me a grade-8 bolt. I suspect that a 5/16" grade-8
bolt isn't going to be made from the fanciest steel, so I can probably
just heat it up and chuck it into water, temper, and have something no
worse than without heat treating at all, but that's not exactly the
most scientific way to get 'er done.

Thoughts? Suggestions? It'd be fun to turn these out of drill rod,
except (a) I don't have any that big, and (b) I don't have a lathe
right now (boo hoo).

I'd kinda like to do this on the cheap, but if McMaster has just the
right thing (they don't) I'd at least like to know so I can feel
virtuous about the money I'm saving.


Update: the 5/16" carriage bolt seems to work. I bashed flats into the
head with a hammer (in an attempt to get a bit of depth) and filed the
resulting lips flat. The original bolt has a 710 mil diameter circular
head with flats that are about 550 mils across; the carriage bolt is
smaller around than this, but I made it's flats to fit closer to the
channel in the cross-slide base.

So if anything happens now it'll be the somewhat undersized head of the
carriage bolt rounding off in the channel. Or the other original bolt
going south...

I'm going to use it, and Real Soon Now I'll either make some bolts per
the original, or I'll make some T-nuts out of 3/4" stock with
appropriate flats milled/filed/ground/hacked in, for use with regular
cap screws. If I get my hands on something I can harden I may even use
that.


Maybe try and determine what T slot standard your lathe uses, you may be
able to buy the T nuts more cheaply and they will likely be case
hardened. I had a look at this recently as I made a T slot table for the
cross slide of my Harrison M300 and looked at the various T slot sizes I
had, the BP set was predominant but the size used on a 10" Vertex rotary
table won out at 7/16" T slot as far as I could tell. IIRC there are old
and new ISO standards with differing dimensions and the inch size T slot
standard. For the Vertex table that I have I made T nuts to suit the
slots and to suit the 1/2" Whitworth clamping kit even though the T
slots appear to be 7/16" spec.

I would be surprised if these particular ones are standard -- the slot in
question is circular, and buried in my cross-slide base.

But there are others I'd like to buy for -- where are these standards
published? Machinery's Handbook? And where does one by anything but bog-
standard ones?

--
www.wescottdesign.com

On Tue, 29 Dec 2009 16:06:57 -0800, Roger Shoaf wrote:

"David Billington" wrote in message
...

Maybe try and determine what T slot standard your lathe uses, you may
be able to buy the T nuts more cheaply and they will likely be case
hardened. I had a look at this recently as I made a T slot table for
the cross slide of my Harrison M300 and looked at the various T slot
sizes I had, the BP set was predominant but the size used on a 10"
Vertex rotary table won out at 7/16" T slot as far as I could tell.
IIRC there are old and new ISO standards with differing dimensions and
the inch size T slot standard. For the Vertex table that I have I made
T nuts to suit the slots and to suit the 1/2" Whitworth clamping kit
even though the T slots appear to be 7/16" spec.

I agree Enco sells Tee nuts down to 1/4 20 already heat treated.

But I've tried that, and gotten tee nuts that don't fit.

My table has a T-slot that matches what Enco sells except for the height
of the 'top' bar of the T, which must be ground down:

.---.
| |
.---' '---. ------
| | this height is too big
'-----------' ------

And I can't see where they have dimensioned drawings of their tee nuts
(nor, for that matter, does a search on 'tee nut' get me a nut to fit in
a T slot).

It would be nice to get the right thing.

--
www.wescottdesign.com

On Tue, 29 Dec 2009 18:39:50 -0600, Tim Wescott wrote:

On Tue, 29 Dec 2009 16:06:57 -0800, Roger Shoaf wrote:

"David Billington" wrote in message
...

Maybe try and determine what T slot standard your lathe uses, you may
be able to buy the T nuts more cheaply and they will likely be case
hardened. I had a look at this recently as I made a T slot table for
the cross slide of my Harrison M300 and looked at the various T slot
sizes I had, the BP set was predominant but the size used on a 10"
Vertex rotary table won out at 7/16" T slot as far as I could tell.
IIRC there are old and new ISO standards with differing dimensions and
the inch size T slot standard. For the Vertex table that I have I
made T nuts to suit the slots and to suit the 1/2" Whitworth clamping
kit even though the T slots appear to be 7/16" spec.

I agree Enco sells Tee nuts down to 1/4 20 already heat treated.

But I've tried that, and gotten tee nuts that don't fit.

My table has a T-slot that matches what Enco sells except for the height
of the 'top' bar of the T, which must be ground down:

.---.
| |
.---' '---. ------
| | this height is too big '-----------' ------

And I can't see where they have dimensioned drawings of their tee nuts
(nor, for that matter, does a search on 'tee nut' get me a nut to fit in
a T slot).

It would be nice to get the right thing.

Ha -- McMaster has 'em, a nice dimensioned drawing and a bunch of
choices, with either fully tapped holes or blocked on the bottom.

They just cost more...

--
www.wescottdesign.com

In article ,
Tim Wescott wrote:

On Tue, 29 Dec 2009 16:06:57 -0800, Roger Shoaf wrote:

"David Billington" wrote in message
...

Maybe try and determine what T slot standard your lathe uses, you may
be able to buy the T nuts more cheaply and they will likely be case
hardened. I had a look at this recently as I made a T slot table for
the cross slide of my Harrison M300 and looked at the various T slot
sizes I had, the BP set was predominant but the size used on a 10"
Vertex rotary table won out at 7/16" T slot as far as I could tell.
IIRC there are old and new ISO standards with differing dimensions and
the inch size T slot standard. For the Vertex table that I have I made
T nuts to suit the slots and to suit the 1/2" Whitworth clamping kit
even though the T slots appear to be 7/16" spec.

I agree Enco sells Tee nuts down to 1/4 20 already heat treated.

But I've tried that, and gotten tee nuts that don't fit.

My table has a T-slot that matches what Enco sells except for the height
of the 'top' bar of the T, which must be ground down:

.---.
| |
.---' '---. ------
| | this height is too big
'-----------' ------

And I can't see where they have dimensioned drawings of their tee nuts
(nor, for that matter, does a search on 'tee nut' get me a nut to fit in
a T slot).

It would be nice to get the right thing.

I've had that problem matching new T-nuts or T-bolts to older equipment,
but it's easy to fix. The T hardware is hardened, but for toughness,
not hardness, and an end mill has no problem cutting this hardware to
size. HSS mills work, and of course carbide really works.

But before doing that I would try metric T-Nuts and T-Bolts, as I bet
that the Smithy is made in China.

Nor is it particularly hard to make a custom T-Nut.

Joe Gwinn

"Tim Wescott" wrote in message
...

I agree Enco sells Tee nuts down to 1/4 20 already heat treated.

But I've tried that, and gotten tee nuts that don't fit.

My table has a T-slot that matches what Enco sells except for the height
of the 'top' bar of the T, which must be ground down:

.---.
| |
.---' '---. ------
| | this height is too big
'-----------' ------

And I can't see where they have dimensioned drawings of their tee nuts
(nor, for that matter, does a search on 'tee nut' get me a nut to fit in
a T slot).


http://www.use-enco.com/CGI/INPDFF?PMPAGE=763&PMCTLG=00

The drawings are just to the right of the listings. They show metric and
regular Tee nuts, and even if you have to grind the tops a bit, the nuts are
case hardened and you can order the right length studs and case hardened
nuts to go along with them.

By the time you fabricate, heat treat and oxide coat the end result, you
will have a bunch of time into a part that costs only a few bucks.


--
Roger Shoaf
If you are not part of the solution, you are not dissolved in the solvent.

On Dec 29, 10:51*pm, "Roger Shoaf" wrote:
...
By the time you fabricate, heat treat and oxide coat the end result, you
will have a bunch of time into a part that costs only a few bucks.
Roger Shoaf

You will also have one you can't really trust, used where the lathe or
operator could be injured if it fails.

I experiment with heat treating for cutting tools but not for strength
items. I turn those down from larger Grade 5 or 8 bolts and often
proof test them. Grade 5 cuts very nicely with HSS, or decent hand
tools. In my limited experience Grade 8 heads and shanks cut easily,
the rolled threads may be harder and nearly brittle.

Bolts aren't expensive relative to O-1 drill rod large enough to form
the head and you can buy another identical one to test to
destruction.

Here is a start toward a homebrew tensile strength tester:
http://www.harborfreight.com/cpi/cta...emnumber=65613
http://www.harborfreight.com/cpi/cta...temnumber=5511
I did a quick test and the scale was within a few % of my bathroom
scale. You can use rope and pulleys to multiply its range, plucking
all the ropes to equalize them.

jsw