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View Full Version : Tip for Mill/ Drill Vise Bolts- Carriage Bolts!



toolmaker76
09-14-2010, 11:57 PM
I have been needing to do some work on my recently acquired mill/drill. I have a set of hold down clamps ordered, but they were back ordered and won't be here for a few days yet- but my new Glacern vise is already here!

The slots are 14mm wide at the top, 24 at the bottom. I went to the hardware store thinking that I would just get some 1/2" hex head bolts, and shim the heads in the slot so that they won't turn. I had already picked out two, when I noticed the carriage bolts in the next bin.

What drew me to them was that they are square at the base, same dimension as the radius, which alone would prevent them from turning in the slot. Then I noticed that there is quite a bit more width on that circular head!

Bought two of them, used the bench grinder to put flats on them parallel to the flats. The bolts fit the slots perfectly, the flats keep them from turning as you tighten them down- and I now have my vise mounted.

Spent the rest of the time I had alloted in the shop today doing mill projects! Thought I would pass that along- my first project was going to be some T-nuts for the mill, but I don't think I need them now!

wierdscience
09-15-2010, 12:31 AM
I think carriage bolts are the duct tape of the bolt world,literaly thousands of uses.

And they also come in grade 8.

Black_Moons
09-15-2010, 04:35 AM
Grade 8 carriage bolts? hmm, I could sware all the bins iv seen of them are usally grade 3.. maybe 5.

Still, Useful bolt. Another good trick: Heavy hex bolts can be ground down into nice T bolts with nothing more then an angle grinder and lots of test fiting. Especialy useful for the compound swivel: you can grind them with a tiny inside/outside radius and have a perfect fit!

Metric also seem to have larger heads then normal hex for a given thread size.

MotorradMike
09-15-2010, 08:32 AM
The carriage bolt idea sounds good in a pinch if you don't tighten them too much. 'T' nuts spread the load out with larger area.

Maybe I'm paranoid but I worry about damaging the table by overtightening clamping bolts.

Ian B
09-15-2010, 10:48 AM
Mike

I have the same paranoia. The only time I really tighten on tee bolts is when the thing I'm clamping is in contact around the bolt, such as a vice base. I made some longer tee nuts up to spread the load, which helps to calm the nerves, but I'm still dreading that "bang" as the tee nut comes up through the slot...

Ian

Al Messer
09-15-2010, 11:32 AM
Mike

I have the same paranoia. The only time I really tighten on tee bolts is when the thing I'm clamping is in contact around the bolt, such as a vice base. I made some longer tee nuts up to spread the load, which helps to calm the nerves, but I'm still dreading that "bang" as the tee nut comes up through the slot...

Ian


Make some "T Bars" to spread the load even more with some flat stock milled to match the slots and some plain "all thread". Or if you want to spend a little more time on them, Thread the hole in the bar, run in a piece of CR rod until it bottoms out, cut off and then thread the "top" end for a hold down nut. Lots of ways to skin a cat without ruining your "T" slots.

derekm
09-15-2010, 03:05 PM
I have been needing to do some work on my recently acquired mill/drill. I have a set of hold down clamps ordered, but they were back ordered and won't be here for a few days yet- but my new Glacern vise is already here!

...
Spent the rest of the time I had alloted in the shop today doing mill projects! Thought I would pass that along- my first project was going to be some T-nuts for the mill, but I don't think I need them now!

been there done that.I Used the carraige bolts to hold the vice to make the T-Nuts.
Carraige bolts really dont have enough area and could breakthe bed of the mill.:eek: You should really only use them as a bootstrap to doing it properly.

Roughly:
the 2x length of the t-nut x thickness of bed x strength of cast iron > cross section area of bolt x strength of bolt.