Looking for bench vice jaws

[Tony Zona]

I’ve been pondering that.

What kind of steel or bar stock?

[Eric Danstrom]

Hack saw/fresh blades, file, drill press and a couple beers are all I need (and my collection of drill bits).

For material I've got a bin with steel scraps, I have something in there that would work.

Ebay sellers have all sorts of metal in all sorts shapes. I found good candidates in the Metal Sheets & Flat Stock section of Raw Materials under Business and Industrial catagory. For example I found 4140 Alloy Steel Rectangle Bar, Unpolished Mill Finish, 3/8" x 1" x 12" for $16 shipped. I didn't post a link but there literally tons of product in that category (And I literally used "literally" correctly!)

[John K Jordan]

I’ve been pondering that.

What kind of steel or bar stock?

I checked a couple of my vises. The jaws on one is cast iron and the other looks like mild steel. You can test your old jaws to see if they are hardened - use a triangular file or the corner of a flat file and try filing on the metal. If the jaws are cast iron or unhardened steel, you will be able to cut into the metal. If the jaws are hardened the file will not bite but just skate.

Cast iron can be soft and brittle and can break with too much force. Mild steel is moderately soft and may bend or deform with force but won't break. Hardened steel can be brittle if improperly annealed but it is very hard and won't dent or wear easily.

A quick google search shows there is controversy over whether to use soft or hardened jaws. Depend on what you are doing with the vise. Here is one opinion: https://wiltonviseparts.wordpress.co...hy-it-matters/

From the fact that yours are broken makes me suspect they are either hardened and not annealed or made from cast iron.

The choice between mild steel and hardened steel is a tradeoff. Hardened and annealed tool steel jaws would grip well and last a long time but would be more likely to mar things held tight in the jaws. But you can't easily saw or machine hardened steel. You have to buy it unhardened, shape and drill, then heat treat, not necessarily easy. Oil-hardening tool steel (O1) is fairly straightforward to heat treat - heat until a magnet won't stick to it and quench in oil, then anneal in a toaster oven for several hours (at 400F if my memory hasn't failed). You can find youtube videos of how to do this with a little propane torch forge/kiln home-made from a couple of fire bricks - knife makers build them to harden their blades, for example: https://www.youtube.com/watch?v=ifTIuNt3aNY

Mild steel is easy to work, less likely to mar the work, but perhaps won't grip as well and would wear more quickly with extreme use. But no heat treating required. Given the choice, I'd use mild steel. BTW, I have a lot of steel stock on hand but if I don't have the sizes I need I usually buy from Online Metals. Short pieces of cold-rolled mild steel are pretty cheap.

Either way, to make a jaw just cut the stock to size, mark and drill the holes for mounting, countersinking as needed, then file a pattern in he jaw face for gripping if desired. A thin abrasive metal-cutting disk might be good for that.

JKJ

[Tony Zona]

Is mild steel 1018 cold finish ok?

[John K Jordan]

Is mild steel 1018 cold finish ok?

This page has good descriptions of the various types of cold-rolled steel:
https://www.onlinemetals.com/en/product-guide
First select the type of metal, "Cold Roll" in this case, find 1018, and click on "Learn More..."

I find this a useful way to decide what alloys to buy, especially with aluminum and brass. For example, if I want brass for machining it explains why 360 is good.

JKJ

[Rob Luter]

Is mild steel 1018 cold finish ok?

It will be fine. It will have a rolled surface finish free of scale. It will be relatively soft and easy to work with.

[Eric Danstrom]

I just checked my original jaws and they are not hardened. I don't know if hardened jaws are better but if/when my jaws fail I won't worry about hardening the ones I make to replace the originals.

[Tony Zona]

I always assumed these jaws were special steel, but after all you people have said, I looked closer. A triangle file hacked right into the broken one. Thanks Mr. Jordan.

Right now I have a project going, but next i will take a stab at making jaws. I went looking through scrap and I think I have steel to use.

Thanks everybody. . . . And I always thought vice jaws were some special magic.