×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Contact US

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Broach Internal Square Drive?
4

Broach Internal Square Drive?

Broach Internal Square Drive?

(OP)
Newbie here.  Anyone have any experience broaching an internal square drive (1/2") in the end of a 17-4 PH stainless steel threaded shaft?  The 2" shaft currently has a 1.5" hex drive on the end of it, but due to interference with another part needs to be cut off and an internal drive put in it. It's also hardened to Rc 38-45, so that may complicate matters.  Any advice? Can it be done?
Jim

RE: Broach Internal Square Drive?

EDM.

Mike Halloran
Pembroke Pines, FL, USA

RE: Broach Internal Square Drive?

(OP)
Thank you both!  The rotary broaching site is very informative.  I don't have experience with EDM so this may sound ignorant, but can it be controlled closely enough to create an accurate internal square drive within the same tolerances as broaching?
Jim

RE: Broach Internal Square Drive?

Yes.

RE: Broach Internal Square Drive?

and another Yes for EDM.
Have you looked at an external 12 point configuration?  That might be easier.

= = = = = = = = = = = = = = = = = = = =
Corrosion, every where, all the time.
Manage it or it will manage you.
http://www.trent-tube.com/contact/Tech_Assist.cfm

RE: Broach Internal Square Drive?

(OP)
Thanks.  For various reasons I am restricted to internal for this one application only.  I'll do a little browsing on EDM, since I only know vaguely what it is.

RE: Broach Internal Square Drive?

How many pieces are you talking about here?  For production quantities I would look at broaching.  For small batch quantities, EDM will be more cost-effective.  As to EDM, you can hold 0.0001's (inches) depending on the time you're willing to put into the process and the surface finish you want.

Cost detractors to broaching: machine costs and specialty broaches.  That hardness is going to be hell on the cutting edges long term (e.g. production quantities).

Cost detractors to EDM: machine costs and the cost of graphite for electrodes (if using a sinker).  Wire costs aren't bad if you can cut straight thru (wire EDM).  It all depends on what the part looks like.

You'll also want to look at how difficult the fixturing of the piece may be.  Is the shaft long, part of a sub-assembly, etc.?  That will affect your tank size, and thus potentially the shop that can burn the piece for you.

RE: Broach Internal Square Drive?

(OP)
Thanks everyone, but it was only one part and has now been sent out to do. I took the easy route: identifying the desired dimensions/specs and letting the shop we sent it to determine how best to achieve it.

RE: Broach Internal Square Drive?

"Letting the shop decide how best to do it" may be completely fine in your application, but sometimes manufacturing methods (or their potential effects) must be fully understood and carefully weighted by the engineer designing a part (or a repair), and not left up to shop making it.  Examples: thread330-96252 and thread2-104510

RE: Broach Internal Square Drive?

(Kenneth- Absolutely, ever seen what EDM does to fatigue life?)

RE: Broach Internal Square Drive?

Yup. My point exactly (and the subject covered in the thread links I provided).

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members! Already a Member? Login



News


Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close