View Full Version : tool bit identification

03-12-2006, 08:41 PM
I went through my box of assorted tool bits today, ones I have picked up in odd boxes at swap meets, given to me, came with lathes, etc., and I see I have 6 or 8 stamped REX AAA on them. Size is 5/16 sq, by 2" long. Does anyone know what grade these are? I have used a couple of mystery tool bits from this collection that were not ground finish, look like they had just been rolled out, and they were not too hard. I haven't tried these REX bits yet. They are not "ground and polished" as tool bit stock usually is, but have machine marks on them. Still somewhat smooth, sharpish corners, and cut at an angle at each end.

J. R. Williams
03-12-2006, 08:56 PM
The tool bits are an old high speed steel and will give good service. Use care when grinding to not overheat the bit.


Forrest Addy
03-12-2006, 10:21 PM
Don't be misled by the finish. Rex AAA is good stuff.

03-12-2006, 11:57 PM
As always a google on REX AA or AAA will source the manufacturers info and comparisons with other tool bit formulas.

03-13-2006, 07:31 PM
Thank you very much. I won't be afraid to spend some time grinding on them now.

03-13-2006, 07:37 PM
And Forrest, I enjoy your articles in the HSM, The New Hand. Some of it I know, but always I learn something and you are able to insert some amusment too. Loved the line on drill bits, "They make drill bits long so apprentices can learn to sharpen them", or some such, I don't think that is an exact quote. I have used that some now when trying to show others how to sharpen their own drill bits free hand. Missed you in the latest issue.

03-14-2006, 12:16 PM
I got a bunch of Rex AAA 1/2 bits off of ebay. They have this black looking finish, but they grind and cut great. As good as Mo-Max or any other well known brand.

03-14-2006, 08:08 PM
Thanks jkilroy, as I said above, now I feel better investing some time in grindig them as needed.