How hard can you get steel? Looking to make a file guard

Discussion in 'Shop Talk - BladeSmith Questions and Answers' started by Leon Husock, Jul 31, 2019.

  1. Leon Husock

    Leon Husock

    Jul 17, 2019
    I find myself needing a file guard lately, but they're all a bit expensive for me ($100-150), likely because carbide is a pricey material. I know we generally test whether a blade is hardened by seeing if a file skates; is there a particular alloy steel that I could heat treat for absolute maximum hardness and use as the face of a homemade file guard? Thanks for any advice you can give!

    P.S. I'm new to the forum, so apologies if there was a better place/way to ask this, or if the answer is easily found somewhere and I just missed it. Thanks again, guys.
  2. Backyard


    Jul 19, 2019
    O1 hardened to low 60s like 63 should work for quite a while.
  3. Metalhead0483


    Jan 17, 2008
    So long as it's harder than the file...
  4. M.McAlevy

    M.McAlevy KnifeMaker / Craftsman / Service Provider Knifemaker / Craftsman / Service Provider

    Feb 16, 2014
    Buy one with carbide inserts and don't look back. It will become one of the best 'bang for the buck' tools in your knife shop.
    Hengelo_77 and WValtakis like this.
  5. Leon Husock

    Leon Husock

    Jul 17, 2019
    I'm definitely planning to in the future, but for now I have a lot of "lets me do a thing I otherwise couldn't do" tools to buy, whereas to me a file guide feels like a "makes stuff I can already do easier and better" kind of tool.
  6. scott kozub

    scott kozub Basic Member Basic Member

    Jan 1, 2018
    I have one I that I made but have been considering getting a good carbide one. How well do they hold up on the belt grinder? I work with AEB-L and do my grinding post heat treat and I'd hat to make a mess of the carbide inserts with a ceramic belt.
  7. tim37a


    May 18, 2010
    I doubt that a ceramic belt would touch carbide inserts. Bruce Bump, please chime in.
  8. Stacy E. Apelt - Bladesmith

    Stacy E. Apelt - Bladesmith ilmarinen - MODERATOR Moderator Knifemaker / Craftsman / Service Provider

    Aug 20, 2004
    I use a Bruce Bump guide and ceramic belts have not done anything to it.
    WValtakis likes this.
  9. Bill DeShivs

    Bill DeShivs KnifeMaker / Craftsman / Service Provider Knifemaker / Craftsman / Service Provider

    Jun 6, 2000
    You can make a serviceable guide out of 2 pieces of angle iron with bolts welded in and holes on the other side.
    It will wear easily, but you can make another in about 15 minutes.
    Natlek likes this.
  10. Backyard


    Jul 19, 2019
    For a cheap (relative) carbide file guide, you can purchase some carbide bars from ebay and epoxy them to a steel base
  11. Natlek


    Jun 9, 2015
    I have two , one with HSS/67hrc/ steel and two with ceramic tile.......I like more this one with ceramic tile I use with angle grinder to speed up things and other one for fine tuning .........
    PS . I don t use them on grinder ,I use them only for work on hidden tang knives...
  12. robwil


    Aug 18, 2007
    An option I have used is removing the teeth from the side of the file that is going up against the guide, and that protects the guide from wear.
    allenkey likes this.
  13. coldsteelburns


    Aug 2, 2010
    If you happen to buy one, I'd say get one depending on how you plan on using it. If you want to use it mostly at the grinder I would say get one with carbide, but if you plan on using a file I'd say get hardened steel one, because the carbide will kill the teeth on your files much faster, and you can't use diamond needle-files since they bite into the carbide and will eventually create grooves where the file rest on the faces.

    But yea, if you're only looking to make your own and are also going to heat treat it yourself then you can get something like O1 (as mentioned) in about 1/4"+ thickness by 1" wide, 3/8" thick would be even better, then drill holes through one of the halves for bolts and for lineup pins if you plan on using them and use that half as a template to drill the holes through the second half. Next, harden and also temper them at around 300-350F for a couple hours to stabilize the martensite, then bolt them together (and also pin if using those as well) so you can grind/sand the faces so they're flat and also square in relation to their sides, and finally finish them up using on a plate surface (i.e granite or glass) and lap them with some sand paper, probably at least up to 400 for a smoother/flatter finish. You can grind them flat before hardening, but I'd still finish them up afterwards in case the steel moves a bit during the quench.

    There are other ways of going about it, but maybe these suggestions will help ya get started.

    My Youtube Channel
    ... (Just some older videos of some knives I've made in the past)
  14. Natlek


    Jun 9, 2015
    Guys , I can cut ANY steel with cutting disk on angle grinder . I CAN T even scratch ceramic with same disk...................
  15. Metalhead0483


    Jan 17, 2008
    I believe the OP is specifically asking about a file guard. If we're talking about belt or angle grinders it'll be a different conversation.
  16. Ken H>

    Ken H>

    Dec 31, 2011
    OP asked how hard could steel be hardened to - 1080/84 or 1095 can easy hit 65 Rc or better from Quench a 300F temper.
    Metalhead0483 likes this.
  17. Big Chris

    Big Chris SAHD/Knifemaker Knifemaker / Craftsman / Service Provider

    Apr 1, 2010
    I have a Bruce Bump Carbide file guide and like it a lot.
    I put it on a tapered tang once to grind in my plunges and one of the carbide surfaces fell out.
    No worries, it was my fault for doing something I don't think it was designed to do.

    I do have one I made from O1 many years ago that is getting all my plunge grind work now.
    I've probably used it on close to 100 knives in the last year or so.
    While some minor wear is apparent it's still getting the job done just fine.

    O1 quenched and tempered at the lowest setting my oven would do is working/holding up just fine.
    Ken H> likes this.
  18. Larrin

    Larrin Gold Member Knifemaker / Craftsman / Service Provider Gold Member

    Jan 17, 2004
    The answer is around 72 Rc, maybe 73.
    Jason Volkert likes this.

Share This Page