PDA

View Full Version : Broach Styles (A, B, C, etc.). . .what's the difference?



atomicjoe23
01-09-2013, 04:37 PM
I was looking at individual broaches today on the Dumont website and see a wide variety of broach styles (A, B, C, etc.) many with the same dimensions available. I tried to find information about the broach styles both on the Dumont website and in the Machinery's Handbook and was unable to find any information. Could anyone shed some light on this for me? I am primarily interested in American Standard push-through keyway broaches (inch) at this point in time, but I will take additional information for future reference as well.

sch
01-09-2013, 04:55 PM
Two parameters: width of slot and diameter of work. A covers small 1/16 to 1/8 width slots upto 1/2" diameter shaft, B takes over at 1/8" or 3/16" slots in 1/2 to 7/8" diameter shafts and so on. Slight overlaps at the crossover shaft or slot size. Inferrence from page: http://www.dumont.com/broaches/keyway-sets/american-standard/

Stepside
01-09-2013, 05:33 PM
SCH pretty well covered the original question. Some added advise would be 1) If possible a ratchetting Arbor Press for the larger/longer broaches. I think you get a much better feel" with the arbor press compared to a hydraulic press. 2) Don't skimp on the cutting oil. I use A9 for Aluminum and thread cutting oil for steel and brass. 3) The broaches hate to being dropped on concrete floors (learned the hard way)

Toolguy
01-09-2013, 07:42 PM
The A,B,C refers to the width of the slot in the bushing. The back of the broach is a standard width to fit the bushing. The cutting teeth can be as wide as the broach or thinner. Once you reach a certain width you have to go to the next size up to make a wider slot in the part.

oldtiffie
01-09-2013, 08:03 PM
http://en.wikipedia.org/wiki/Broaching_(metalworking)#Types

from:
http://en.wikipedia.org/wiki/Broaching_(metalworking)

and:
http://www.google.com.au/#hl=en&sugexp=les%3B&gs_rn=1&gs_ri=hp&cp=8&gs_id=1n&xhr=t&q=abc+broaches&pf=p&tbo=d&rlz=1W1IRFC_enAU360&sclient=psy-ab&oq=abc+broaches&gs_l=&pbx=1&bav=on.2,or.r_gc.r_pw.r_qf.&bvm=bv.1357316858,d.dGI&fp=1b06cd1115cee478&biw=1920&bih=818&bs=1

J Tiers
01-09-2013, 09:34 PM
Since some are offering advice, and not answering the question...... may as well jump on too...

If you look, you will probably find a minimum THICKNESS of material to broach for each size of broach..... basically it is the saw rule, three teeth in the work.... If you don't have enough teeth in the work, the broach can go off line, take much bigger bites, be very hard to operate, get "sucked into" the cut, etc..... All bad.

You need a minimum thickness of material to make the broach work right.

Paul Alciatore
01-09-2013, 10:35 PM
I am not a broach expert, but the styles refer to keyway broaches for cutting keyways on components installed on a shaft. The A, B, C, etc. designations seem to correspond to the width of the broach. But this is NOT necessairly the width of the keyway that it cuts. So a 1/16" broach would cut a 1/16" wide keyway but it could be a A, B, or even larger style. The style indicates the overall width of the broach and the width of the slot in the bushing you need to use it. So a 1/16", A style broach would cut a 1/16" wide keyway but needs a bushing with a 1/8" wide slot.

The A style would be for broaches up to 1/8", the B style for broaches up to 3/16" etc. Look here for a partial list of combinations"

http://www.mcmaster.com/#catalog/118/2514/=kyv3xj

The style letter designation will match a broach to a bushing. An A style broach needs an A style bushing, B with B, C with C, etc. You can't mix them.

atomicjoe23
01-09-2013, 10:52 PM
Thanks for the responses guys. . .I thought it might be more involved than that. I never paid very much attention to the broach sets in the shop. . .since they are in sets in a box and I had never needed to order one I didn't realize there were different styles. Pretty straight forward. . .appreciate the help.