The Home Machinist!

where could one source such a thing inexpensively. I am looking to fab. a grain mill, but I don't think a little 6x18 atlas would be up the the job of knurling a 1" diameter stainless round. If I had the rollers, the rest would be time consuming, but doable. eccentric adjustment for roller gap/crushing degree, hopper, motor. All that is possible with my equipment. But the rollers?

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atlas 618,MM challenger wire welder, 4x6 cheapo bandsaw, assorted junk, spears for hunting mastadons.

you need a serious size machine to do it well in hard materials

You'd probably do just fine if you'd choose a scissor type knurling tool. The big problem you'd most likely have is in getting the machine to run slow enough. That may or may not be possible. You would be expecting far more than a small machine could provide if you selected a typical knurling tool, however.

Stainless isn't necessarily hard, and often is not. Certainly none of the 300 series alloys are---but with rare exception (203S & 303S & Se) they're tough---which is not to be confused with being hard. They demand slower speeds and greater power for the cuts, but they can be well managed with the use of HSS tools with respectable positive rake and lighter feeds. With proper tool geometry, they all yield quite nice surface finishes. None of these grades make great bearing surfaces, however.

If you'd like to pick a material that is non-corrosive, and has excellent machining characteristics, think about using 416. It is the best of all grades for machining, and offers the opportunity to be heat treated.

Harold

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Wise people talk because they have something to say. Fools talk because they have to say something.

I have seen knurled shafts that looked knurled at first glance, but weren't. They were spiral milled with an index head on a mill with a universal table. In this way you can be as coarse as you want with out any great forces being required. Often done for large feed rollers for the lumber industry.

Richard W.

Are you using a plan for the grain mill? My wife grinds her wheat and I think her's uses a disc grinder (noisy bugger, grab the ear muffs).

Can you post the plans here?