Small instrument vise, 25th-year issue

Regarding the "Small Instrument Vise" article in the recent anniversary issue...

Would it be alright to make this from cold rolled steel (1018) or even drill rod (what you Brits call "silver steel"?

I have plenty of 1/2" cold rolled steel. I also have 3/4" drill rod, but I imagine it'll take considerable work on my mini-mill to get it down to 1/2" square.

The article mentions "bright mild steel" and "EN8". I know nothing of such concoctions.

Mike

Mike,

EN8 is a medium carbon steel (0.4% Carbon) and has an ultimate strength of approximately 50 tsi (tons per square inch); the direct American equivalent steel grade is 1040.

1018 is a low carbon steel with an ultimate strength of approx 27 tsi so not a good substitute.

Drill rod is a 1% carbon steel and in its 'as supplied condition' also has an ultimate strength of 45 - 50 tsi so would be a good substitute provided no post machining heat treatment is called for as that would through harden the component and make it brittle.

Steve

Edited By steve de24 on 03/08/2015 00:08:39

All of which is fine Steve, if the ultimate strength is the limiting factor of the design.

For the Small Instrument Vice in the 25th Anniversary Edition, I can't believe it really matters. Personally, I'd use whatever steel I had to hand that was reasonably easy to work. Or even brass for a soft-jawed version.

Edited By Bandersnatch on 03/08/2015 01:44:17

UK: Bright mild steel = US: cold rolled steel.

Good luck Mike, post a photo when you finish it!

I'm tempted to make it myself - I tend to use one of my ever-rowing collection of (mostly ratty) clamps whenever I need a small vice, and a nice neat hand vice would be a boon.

Neil

Edited By Neil Wyatt on 03/08/2015 09:03:17

I finally got around to making this. It has a few mistakes, but I almost finished it today.

I have the clamping screw chucked in the lathe right now with no good idea how I'm going to cut the 0.040" radius groove. I do have a small set of imperial radius gages with 3/64" being the closest, but it seems unlikely that I could grind an appropriate tool bit. Any thoughts?

Also, I accidentally reamed the moving jaw guide pin hole too large, at 0.251" or so. I wrapped a piece of brass shim around the guide pin and it looks like I should be able to press it into the jaw. Will this be alright, or should I go with high-strength Loctite?

Mike

Typo: should be 5/64", not 3/64".