DIY HSS-Bit Taper Grinding



  • I asked around a bit..

    We have a couple of Rawl holders and fistfull of #12-14 bits (thank you BooDawg!)

    More on that later..

    A while back I bought a Rawl holder but I had trouble sourcing bits that weren't carbide tipped.

    I bought a couple packages of standard HSS bits with the intention of grinding the taper into them..

    I tried using a drill and sandpaper, but I couldn't get the flutes to align with the chuck.. it was funny for about five seconds.

    I gave up and put a different setup together, which works pretty ok.

    I noticed an ST thread recently where (Tony-Westmrnclmbr?) mentioned DIY grinding taper into HSS bits

    Anyone have an easy way to do this, or a source for A-taper HSS bits?



  • I've never used taper bits so I don't really know the ins and out of them.

    But would these work?

    https://www.mcmaster.com/drill-bits

    alt text



  • Those are too big for the Rawl but work for an improvised setup I've been working

    It'd be nice to have a bunch of sharp HSS bits to fit the rawl.. still searching..

    This is an 17/64" MT1 bit with an improvised hard solid socket handle

    It's about 4oz heavier and is shorter than the Rawl but has a bigger striking surface

    I'll probably end up shaping it some and grinding a groove for a swaged cable

    IMG_3595.JPG

    IMG_3594.JPG



  • @J-Fengel This set-up has worked well for me. Of course when the tip of the drill wears and starts drilling a narrower hole then the bit will seize when you're further in. I suspect this is true of most bits like these. Just keep 'em fresh and you'll be good to go.

    It's for a Milwaukee air hammer, but the big long hexagonal shaft that mates with the chuck is cut, then ground off. The robust drift is a big plus. It uses "A" taper drills. I ground the tip down to the shape I wanted on a standard bench mount grinder. Just go slow, and keep dipping the bit in water to keep it from getting too hot or you'll lose the temper (first its, then yours later when it dulls after about 5 taps up on the wall.)

    You can get the carbide tips as well in this taper.

    Many miles of service from this baby, that's a 3/8 bit...

    Milwaukee-drill.jpg

    I got this stuff at Cutler Steel in Chatsworth (LA)



  • Anyone have a Star handle for sale?



  • Unless you have a lathe with a tool post grinder, trying to modify bits to work with your rawl holder just isn't going to happen

    alt text

    Making a bit holder for available drill bits is a much better plan.



  • @Paul-Hail, is that something you made yourself? Looks nice, anymore photos of the build? HSS, SDS?


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