I need some vise jaws made anyone up for it?

Steve, in order to do this job and get it right, you really need a surface grinder, so the jaws can be ground for straightness, flatness, parallelism and size after a proper heat treat of a suitable material.

Barring the availability of a grinder, you might achieve limited success by using a precipitation hardening steel, something like 17-4 PH stainless, that can be hardened up around 50Rc, without achieving a red heat, or quenching. Warping can be expected when quenching materials, even when handled quite properly.

Harold

As Harold sez:

"> Barring the availability of a grinder, you might achieve limited success by

Nice to know this. I wasn't aware there were precipitation hardening steels. BTW, Harold, how does that process work?

Bob (always looking to harden things) Swinney

yes I sure do (G) I need one to flatten plane irons and infill soles. but after spending 15,000 on my cnc router I am pretty much broke. can someone cut the grooves in a hardened pair of jaws? I don't know how hard it is to work with such material.

So mill/drill them out of low carbon stock and caseharden them. Kasenite is fairly cheap, a trial run wouldn't take too long. If you need ultra-precision, though, you're going to need to get them ground, might as well use air-hardening stock or the like then. Mill the step in matched pairs at the same time.

Stan

Depends on the jaws. If your vise is a Kurt, as you say, the jaws won't lend themselves to machining very well. They're usually heat treated to resist denting and deforming. You might experience success to some degree with a carbide end mill, but when it's all said and done, you still need a grinder to achieve the level of perfection that should be afforded a good vise. It's possible that the jaws will no longer be flat if you remove metal from one side to form the steps, so you'd still need a surface grinder to restore them to a useable condition.

Like you, I'm often irritated at not having the perfect set of parallels at my disposal------but I'd think very long and hard before cutting a step in my vise jaws. While it would serve you fairly well, there would be more times that you wished you hadn't done it than times you're glad you did. You'll come to realize that the depth of the step is rarely what you need for the task at hand, and it creates problems instead of solving them. Only if you run a specific job on a repetitive basis would it be a good idea. Of course, it all depends on what you expect from your tools, and how you use them. I'm speaking from my perspective, which may not fit the bill for you.

Harold

I'm hardly a metallurgist, but as I understand it, certain elements that are alloyed with others have the ability to grow a crystalline structure at elevated temperatures. This growth increases hardness. To put them in solution, they are usually taken to critical temperature, then instantly quenched, locking them in solution. It's much like the carbon cycle in that regard----only softening the material instead of hardening. Once in the solution annealed condition, heating for a prescribed period of time at the proper temperature encourages the growth of specific crystals in the alloy in question. Nothing more than heating and holding is required to develop hardness. To help you when thinking about the process, think of heat treatable grades of aluminum---which work the same way. With 17-4 PH, the hardest condition (H900) is developed at the lowest temperature, which is 900 F.

You're more aware of such materials than you realize, it's the mechanism by which they work that had escaped you. Air hardening tools steels are precipitation hardening materials.

Some of the toughest and hardest of materials are precipitation hardening. They do not rely on the carbon cycle for hardness.

Have you heard of Vasco-Max alloys? Vasco-Max 350 is named after its qualities-----the 350 designates its tensile strength after proper heat treat-----which is to heat and hold----no quench.

Hope that helps (and is right-----as I said, I'm no metallurgist)

Harold

Thanx, Harold ! That is metallurgy enough for me. Your analogy with AH steel was quite explanatory.

You may want to try 4140 milled jaws if you can't find anyone to grind you a good set. Any type of heat-treatment will warp your jaws. Your mill has to be setup correctly, but I think you could machine some fairly accurate steps using a sharp endmill and light cuts.

Tips: Use a new sharp endmill on your finishing passes. Never finish using the side *and* bottom of the endmill at the same time (choose the side *or* the bottom). Make sure the machine is tight (the gibs have to be set up correctly). A finishing cut in 4140 using a sharp HSS endmill is on the range of .0005-.002" DOC (radial *or* axial - again, never at the same time).

Once you think you're done, use a dial test indicator to indicate the entire working face. That will tell you right off the bat if you're alright. Over 6", I would aim for a total deviation of less than about

0.0015".

Regards,

Robin

that's what I was thinking. I can buy them pre made about 120.00 the step is a bit deeper then I wanted it but it should be fine. I am a woodworker first and foremost so I don't do things like a normal machinist will. but most of what I do would be with a 1/8" or so step wood or metal. but I can sure get creative when needed. plus I don't usually need the precision most machinists need.

I put a 3/16" step in my Kurt vise jaws after seeing hundreds of them in machine shops.

And Im glad I did. Works most rickytic.

Gunner

"Liberalism is a philosophy of consolation for Western civilization as it commits suicide"

- James Burnham

Gunner sez:

"> I put a 3/16" step in my Kurt vise jaws after seeing hundreds of them in

Now, Gunner, before I make the bald-assed assumption this was a "monkey see monkey do" sort of a thing; please try to explain what is the purpose of ruining a set of vice jaws in this fashion.

Bob (not a clue) Swinney

Chuckle...

It works great for holding small parts, thin plate etc etc and not having to futz around with parallels that typically will be too short, or too tall, or fall over etc etc.

One must realize that the step does not have huge holding power, but for small stuff, it works very well indeed. Thin stock clamped too tightly will indeed bow. But it will with parallels too.

You have to make sure that the inside corners have no or very little radius, or are even a bit undercut. I roughed em out with a endmill, with the jaws clamping 1-2-3 blocks, then took the entire vise and put it on the surface grinder with cup wheels and dressed em perfectly smooth and flat, then putting it back on the mill, hit the corners just a touch with a dove tail cutter, to give me a tiny amount of under cut.

I use em all the time for drilling, light milling and so forth.

Ever try to machine keystock, put in "push out" holes and such? Can be an utter pain in the ass with parallels. With the small step...simply clamp it in the step and go. Just a single example. Shrug.

Something I learned years ago..if it sounds stupid..but works..it aint stupid.

Gunner

"Liberalism is a philosophy of consolation for Western civilization as it commits suicide"

- James Burnham

I know I can't do it myself unless I go with soft jaws and then they would get chewed up. this company makes them in the sizes I want

but if I want to clamp 1/4" thick stiff the 1/8" step is too much. so if I got one it would work for some but not everything unless I got the .100 step my be a bit small. have to think a bit. but for drilling and the holding I do they would be pretty good. a fair amount of time I mill blocks of wood to do the job when I need wider support. the wavy parallels would work there though

Superglue the parallels that work to the jaws. It isn't permanent.

Wes

yes I have done that. wax the jaws a bit and you can get the glue right off. kurt had a set of magnetic ones but so far I have found anything that attracts shavings is a real pain.

[ ... ]

I've got a set of jaws in a 4" Kurt-II which have permanent magnets inset into the jaws, which does an excellent job of holding onto parallels. (And, unfortunately, also an excellent job of holding onto swarf. :-) But inset magnets may be all that you need, and as long as you keep the parallels in place, they keep the swarf out of the magnets.

No -- the magnets were not my idea -- they were in the jaws of the 4" Kurt-II when I got it from an eBay auction. I don't know whether they were commercial jaws, or shop-made modifications to existing jaws.

Enjoy, DoN.