Grinding hardened steel without power tools?

spareparts · Jun 21, 2012

I've been doing stock removal for a little while on my apartment patio. Lately I just can't get time to work on projects before it gets later in to the evening. Being in an apartment I don't want to turn on the powertools and ruin the neighbors evenings. Not too much of a problem with pre-heat treated steel because I can use files pre-heat treat. I've lately been trying to work on kitchen knives and do much of the grinding post heat treat to avoid warping with my back yard (patio) heat treat process.

Are there any stones, files, or other materials that I could use effectively for grinding hardened steel by hand? I don't mind a bit of extra work, crafting knives is a release for me and helps me cope with stress.

jawilder · Jun 21, 2012

Files and sandpaper. I usually shoot for 61/62 on my kitchen knives, but that would be a pain to do without power tools. I'd shoot for around 58. It should be a bit easier to work.

javand · Jun 21, 2012

Grobet Valtitan files, and/or aggressive water stones. Depends on what you mean by "grinding". Valtitan files are RC72, and will cut hardened steel without much fuss.

There may be jeweler's saw blades that will also? Not sure. Cutting out profiles is going to be the hard part. I'd cut your blanks out soft, HT, then you can easily do your bevels on an aggressive stone or with paper on a surface plate.

parbajtor · Jun 21, 2012

I bought a wooden handled 8" X 7/8" Flat diamond file in 180 grit 6" cutting area. I'd post a link, but I've been warned before about "deal spotting". It cuts pretty good. You can probably get coarser, but I find it to be a good compromise. You can very easily cut too coarse with heat treated steel and not be able to take out the scratches without changing the shape of the blade. My only gripe is that it that every edge is coated,. I'd have preferred one thin edge uncoated.

javand said:
There may be jeweler's saw blades that will also? Not sure. Cutting out profiles is going to be the hard part. I'd cut your blanks out soft, HT, then you can easily do your bevels on an aggressive stone or with paper on a surface plate.

+1 on that. Although I used a diamond file. You'd avoid a lot of work by grinding as much as you can (avoiding warpage) pre HT,particularly full flat grinds or compound bevels. Plus you could try to use normal files as much as possible, to save wear on your expensive diamond file. These files are usually sold individually, not as a set.

EDIT: The company I got the file from is no longer online, but if you google "8" Flat Diamond file" there's something similar on the first page.

spareparts · Jun 21, 2012

javand said:
Grobet Valtitan files, and/or aggressive water stones. Depends on what you mean by "grinding". Valtitan files are RC72, and will cut hardened steel without much fuss.

There may be jeweler's saw blades that will also? Not sure. Cutting out profiles is going to be the hard part. I'd cut your blanks out soft, HT, then you can easily do your bevels on an aggressive stone or with paper on a surface plate.

Pretty much I cut out the blanks and clean them up, drill the holes, too, of course pre-heat treat. Then, when I can use a belt grinder, do the bevels post heat treat, with fresh belts, taking my time and do alot of dunking in a bucket of water to keep the steel cool. But during the week I just want to be able to do some work to unwind and make noticeable progress. This week I'm putting handles on a couple bushcrafters, using files and sandpaper for shaping. It's actually been kind of fun and to get away from electricity for a bit.

lonepine · Jun 21, 2012

Are you doing the complete grind POST heat treat? That seems like overkill to me.

Have you had problems with warping or are you being "proactive" in avoiding it? How thick and what type steel are you using?

- Paul Meske

spareparts · Jun 22, 2012

Using 1/8" and 3/16" steel with blade lengths ranging from 7"-10" x 2"-2.25" wide using Aldos 1084 quenched in canola. I built a kiln out of two freon tanks welded together and have a stainless steel baffle. I've had horrible warping problems when I do a complete grind pre-heat treat. Quite possibly being a ameture and imperfect bevels contribute among other factors. I've been doing experiments with partially grinding just the first half inch or so of the bevel but I still get warps on every other knife, sometimes correctable during the temper. 1/8" isn't too bad grinding post heat treat I find I just have to be extremely careful as I get closer to working the tip. The 3/16" is pretty time consuming, though. I don't mind a slow production rate, these are just for personal use or to give away to family and friends.

Edit: I've been getting good results with bushcraft knives, so I don't feel that I'm taking anything on that's beyond my reach, my obsession with kitchen knives is that I find them so much more difficult to do right. I've done my share of professional cooking so I know what I like and that makes me set the bar. A nice even distill taper to a needle tip combined with a full flat grind almost to the edge with a good balance and the right grip/handle for ergonomics is pretty dang hard to get IMO but that's my goal.

photonjunkie · Jun 22, 2012

Perhaps silicon carbide stones or something like the Mouldmaster from Congress Tools would be another alternative (the Congress stuff is a bit small though)