×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

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!
  • Students Click Here

*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

Jobs

17-4 stainless
5

17-4 stainless

17-4 stainless

(OP)
hello
need help on what kind of drill to use for drilling 17-4 stainless steel in the soft condition.
also what speeds and feeds to use.
.600 deep with .386 dia. drill with no coolant holes-will be bore after drilling.
machined on newer mazak lathe.
thanks in advance

RE: 17-4 stainless

use cobalt drill.

personally i like titex drils but at least in israel the are very expensive.

RE: 17-4 stainless

A reasonable starting point, using a high speed steel twist drill, would be 400 RPM at .005 IPR feedrate.

Manufacturing Freeware and Shareware
http://mrainey.freeservers.com

RE: 17-4 stainless

you suggest cutting speed of aprox. 12 m/s. with cobalt drills you can work with more than double speed.

RE: 17-4 stainless

When machining 17-4PH, you must be very careful not to let the work get too hot.  If it gets too hot, it will harden and become MUCH more difficult to machine.

RE: 17-4 stainless

this is why you must drill it at once.

ih this diameter you can drill with no fear.

RE: 17-4 stainless

Hi punches,

I have had success in drilling 17-4 with the following drill from Guhring:

Series #329

Guhring has a .3858"(letter "W") in their book. It has 1.7" of flute length which will be fine for your hole depth. Start out at 450 rpm with a feed of 2.3 ipm. Do not use the pecking cycle as this may contribute to work hardening of the material.

You will be fine with this drill.

RE: 17-4 stainless

HHS drills work fine in 17-4. If you are drilling alot of holes cobalt will be fine as well.
I work in the sensor industry where 17-4 is a standard material. My company uses about 60-70 tons of 17-4 each year.

As far as speeds for HHS drill I use this little formula 191/drill dia. this works very well.
Sorry to disagree with oithers here but pecking drill 17-4 is not usually a problem you need to break those chips particularly on deep holes. Do flood the area with coolant.

RE: 17-4 stainless

Strange as it sounds, but cobalt or HSS seems to work very well, as long as they are the black oxide coated ones. I have had no luck with the standard M42 or the bright finish HSS.

RE: 17-4 stainless

Here is a Gurhring description off a packet of drill bits we used to drill heat treated 17/4, 455,and 316 SS.   
We used the same type bit up to 8 mm and probably a little larger.  This manufacturing group stayed with Gurhring for all their drilling operation involving the PH alloys.
  
Art. No. 658 K
DIN 338 RN
S-Bohrer GT1
 f 3.28 mm
HSCO EDBB **

These are used for blind holes 22mm to 30 mm deep in hardened PH alloys.     
These are used on highly automated (Burgomaster) drill presses running 24/7/365.  These drill bits are TiN (golden) and are resharpened and recoated several times.  
I think this particular drill bit has been replaced lately with another style Gurhring in the same family, but this type was used for many years.    

I thought I could give you some idea of the feeds and speed but I’m having trouble getting the time of day from the people presently in charge of this operation.

RE: 17-4 stainless

TiN Coated 135 degree point (split point helps).  You can drill forever without a problem.

Fill what's empty. Empty what's full. And scratch where it itches.

RE: 17-4 stainless

OSG has line of drills made just for stainless. They are second to none. I have drilled stainless for 13 years and these are the best. I think they are called EX-Gold series.

RE: 17-4 stainless

You want 135 deg. drill point geometery rather than the standard 118 deg.

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!


Resources