• We want to encourage those of you who ENJOY our site and find it USEFUL to DONATE and UPGRADE your membership from active member to donating or premium membership. If you want to know the differences in membership benefits, please visit THIS PAGE:

    https://www.hobby-machinist.com/premium/

    Donating memberships start at just $10 per year. These memberships are in fact donations that help pay our costs, and keep our site running!
    Thank you for your donation, God Bless You
  • June Project of the Month (Click "x" at right to dismiss)
[4]

Drilling in hardened stainless steel

[3]
[10] Like what you see?
Click here to donate to this forum and upgrade your account!

gzoerner

Iron
Registered Member
Joined
Apr 20, 2016
Messages
29
Likes
45
#1
I'm modifying a Harbor Freight caliper to be used as a DRO on my lathe. A couple of 2 mm holes need to be drilled in it so it can be mounted to the cross-slide. The caliper is definitely hardened stainless. A TiN coated HSS drill doesn't do anything to it. What is the best way do drill small holes in this material? Will M35 Cobalt HSS work? Do I need carbide or diamond drills? Brittle carbide that small will probably be pretty tricky.

Thanks in advance for any help.

Glen
 

4ssss

Active Member
Active Member
Joined
Apr 25, 2017
Messages
365
Likes
208
#2
Try a carbide center drill if you have 1 and see if it will start. I find it hard to believe a HF caliper is hardened. I think you may be trying to drill thru chrome, which would make more sense. If that's the case, just grind off a spot and drill.
 

Silverbullet

Active Member
Active Member
Joined
May 4, 2015
Messages
3,340
Likes
1,605
#3
Try the cobalt but go as slow a speed as you have , but use a heavy feed . Seems I've read or done this before to a hardened steel . Keep it wet with cutting fluid . You might be able to shoot a hole with a plasma cutter . Quick trigger or a pulse .
 

tcarrington

Making miscellaneous parts for years now
H-M Supporter - Sustaining Member
Joined
Dec 27, 2013
Messages
42
Likes
41
#4
ditto on above - carbide is likely required, but what if you changed the design to clamp the part you are trying to drill through? Making fidgety little clamps isn't fun, but mild steel or even aluminum would be OK.
 

RJSakowski

H-M Supporter - Premium Member
H-M Supporter-Premium Member
Joined
Feb 1, 2015
Messages
3,278
Likes
3,723
#5
I have drilled HF calipers with carbide drills. Drilling is best done on a mill where you can control the feed and hopefully have less runout. If using a drill press, use a light touch and watch the the chip formation. Those small carbide drills can break easily. Don't attempt drilling with a hand drill.
 

GoceKU

Active Member
Active Member
Joined
Jul 14, 2017
Messages
512
Likes
883
#6
I'm using Guhring HSCO drill bits they are very special and i've use them on stainless steel weld without any problems, HSS is too soft for continues drilling stainless steel or harden stainless steel.
DSC_0148.JPG DSC_0143.JPG
 

gzoerner

Iron
Registered Member
Joined
Apr 20, 2016
Messages
29
Likes
45
#7
Thanks for all the quick responses.

The jaws of the calipers and the main body are definitely hardened. Fortunately, the slider where the electronics mounts is relatively soft so my TiN HSS drills work just fine. I don't think my skills (or budget) are good enough for small solid carbide drills. I can break small HSS bits easily enough.

tcarrington's suggestion is where I'll go for mounting the body to the lathe. JB Weld to the rescue.

Thank you all again.

Glen
 

Briney Eye

H-M Supporter - Premium Member
H-M Supporter-Premium Member
Joined
Jun 16, 2016
Messages
91
Likes
78
#9
I'm modifying a Harbor Freight caliper to be used as a DRO on my lathe. A couple of 2 mm holes need to be drilled in it so it can be mounted to the cross-slide. The caliper is definitely hardened stainless. A TiN coated HSS drill doesn't do anything to it. What is the best way do drill small holes in this material? Will M35 Cobalt HSS work? Do I need carbide or diamond drills? Brittle carbide that small will probably be pretty tricky.

Thanks in advance for any help.

Glen
I had to drill a couple of holes in a Shars stainless scale to use it for a quill readout on my mill. HSS wouldn't touch it. Cobalt wouldn't touch it. I wound up buying a set of 10 carbide printed circuit board drills for about $7 from Amazon (Prime) that worked just fine.
 

WarrenP

Active Member
Active Member
Joined
Feb 25, 2018
Messages
68
Likes
9
#10
You can use a small grinding bit like a dremel tool. I had the same problem with hf calipers, it defenitely is hardened. I finally was able to use a small diamond grinding bit on it , get one that is round and small 1/8 inch or less...drills wouldnt work for me.
 

randyjaco

Active User
H-M Supporter-Premium Member
Joined
Oct 5, 2010
Messages
777
Likes
277
#11
Have you thought about just grinding slots with an abrasive disk? That's what I usually do to make a cheap DRO for a machine. Much easier than drilling.
Randy
 

kd4gij

Active User
Active Member
Joined
Feb 7, 2011
Messages
4,588
Likes
1,752
#12
Get the smallest masonry bit you can find and drill away.
 

bfd

H-M Supporter - Premium Member
Staff member
H-M Supporter-Premium Member
Joined
Sep 9, 2016
Messages
412
Likes
237
#13
another way to put small holes in hardened materials is to lap the hole. use a small piece of brass (welding brazing rod) and a bit of clay to surround the hole and contain the lapping compound. medium speed and just touch down raise the brass lap and continue until you have a hole bill
 

rwm

Active User
H-M Supporter-Premium Member
Joined
Mar 25, 2013
Messages
1,290
Likes
1,423
#14
I just did this. Carbide was required.
Robert
 
[6]
[5] [7]
Top