How to drill stainless steel?

How to drill stainless steel?

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k-ink

Original Poster:

9,070 posts

180 months

Friday 5th February 2010
quotequote all
I'm having real trouble drilling into stainless steel! Despite just buying the most expensive drill bit I could find in a local DIY chain. I feel like giving up and nuking it from orbit!

Should I just take it to a laser specialist?

elster

17,517 posts

211 months

Friday 5th February 2010
quotequote all
The most expensive doesn't mean the best.

Pilot hole, drilling slowly, lots of lube.

If you drill too fast then the stainless will harden and you will have failed miserably. biggrin

No need for a laser specialist, anyone with a punch will probably do.

It depends on the object and what you want doing.



Edited by elster on Friday 5th February 17:01

timlongs

1,729 posts

180 months

Friday 5th February 2010
quotequote all
elster said:
Pilot hole, drilling slowly, lots of lube.
Haha

k-ink

Original Poster:

9,070 posts

180 months

Friday 5th February 2010
quotequote all
I already failed miserably! And yes, I did use high RPM. This is PH hehe Ok, I will go slower


Now, what lube? I can lay my hands on baby oil or vaseline...

HertsBiker

6,317 posts

272 months

Friday 5th February 2010
quotequote all
timlongs said:
elster said:
Pilot hole, drilling slowly, lots of lube.
Haha
tee hee!

seriously, slowly does it or the bit will spin and overheat.

I bet the best bits or today won't match the tool-steel cutting bits that my father had (now I have them) they can cut machine tools and have no problems with anything. Where are you, and what sized holes? (fnarr)


hairyben

8,516 posts

184 months

Friday 5th February 2010
quotequote all
HertsBiker said:
timlongs said:
elster said:
Pilot hole, drilling slowly, lots of lube.
Haha
tee hee!

seriously, slowly does it or the bit will spin and overheat.

I bet the best bits or today won't match the tool-steel cutting bits that my father had (now I have them) they can cut machine tools and have no problems with anything. Where are you, and what sized holes? (fnarr)
gigglz.

Seriously does this work?

I remember doing a job for a builder- to "save money" rather than buy stainless steel speaker outlets x4 ($$$ from high-end supplier) that "I" should just drill 10mm holes in budget blank plates for the speaker cables, snapped half a dozen small drills (about 3mm, yes drilling slowly) and barely scratched the steel, before throwing it back at him and telling him he could fart faff fk fool about with it if he thought it was such a great idea.

elster

17,517 posts

211 months

Friday 5th February 2010
quotequote all
Yeah I manage to drill stainless ok.

Just slowly and very cool.

A centre punch will help to get strarted rather than just scratching around on the surface.

Also a striaght hole will be better, such as from a pillar drill.

julian64

14,317 posts

255 months

Friday 5th February 2010
quotequote all
Cobalt drills. Machine mart do them. Stainless still isn't a single metal, there are various grades, you will not touch some of the tougher grades with a HSS drill.

All drills, even really tough ones can be buggered by overheating from the wrong speed cut.

tr7v8

7,207 posts

229 months

Friday 5th February 2010
quotequote all
Had SS scuttle plates on the westie when I built it. Use a cobalt drill of the right size, preferably pillar drill & slow speed, feed with plenty of lubrication. Make sure whatever you drilling is clamped down as the drill WILL grab when it breaks through!

Edited by tr7v8 on Friday 5th February 17:35

AndyS2

869 posts

259 months

Friday 5th February 2010
quotequote all
k-ink said:
I'm having real trouble drilling into stainless steel! Despite just buying the most expensive drill bit I could find in a local DIY chain. I feel like giving up and nuking it from orbit!

Should I just take it to a laser specialist?
First of all try a cobalt drill, if you still can't do it post up a pic of what your trying to drill and I'll tell you if it could be done on a laser.

Riggernut

1,681 posts

232 months

Friday 5th February 2010
quotequote all
julian64 said:
Cobalt drills. Machine mart do them. Stainless still isn't a single metal, there are various grades, you will not touch some of the tougher grades with a HSS drill.

All drills, even really tough ones can be buggered by overheating from the wrong speed cut.
+1

sjj84

2,390 posts

220 months

Friday 5th February 2010
quotequote all
Cutting fluid will make all the difference. Use a slow speed and you'll have no problems at all.

S1mon.

536 posts

223 months

Friday 5th February 2010
quotequote all
HSS drill bits will go through stainless sheet with out snatching if ground correctly, this is not what a new drill bit is like, it needs to be nearly flat with a point in the centre. Best if a piece of wood is placed underneath.

k-ink

Original Poster:

9,070 posts

180 months

Friday 5th February 2010
quotequote all
It is a 2.5mm dia hole, in 2mm thick SS sheet. But there are 20 holes to do.

ps

I'm in Maldon, Essex, CM9 smile

Edited by k-ink on Friday 5th February 18:55

5lab

1,668 posts

197 months

Friday 5th February 2010
quotequote all
try and get some pressure downwards on the drill. I had to drill a 8mm hole in the leafsprings on a car once - 1" hardened steel. Was hardly making a mark till I stuck a crowbar between the bodywork and the spring (was mounted at this point) at which point it went through in about a minute. dead easy

skeggysteve

5,724 posts

218 months

Friday 5th February 2010
quotequote all
When I had to drill 40 x half inch holes in a 2 mm SS plate I choose the easy option - I went to a local engineering company! £20 job done!

GAjon

3,740 posts

214 months

Friday 5th February 2010
quotequote all
If you have already got the metal to hot, ie the bit and the steel have gone red hot whilst trying to drill it, you will struggle to go through it a second time.
Try a fresh or resharpened drill from the other side of the sheet if you can.
Centre punch the hole.
Drill sqaure to the sheet, medium speed, even pressure, but not to much, loads of coolant lube.
If you see the tip of the drill or the sheet going red, stop, let it cool and try again.
A normal HSS drill should do it, but once the edge of the drill is gone you need to resharpen it.
Also stainless has hard spots in it, so some holes may go through easier than others.

wagon and horses

12,231 posts

195 months

Friday 5th February 2010
quotequote all
Probably best to find your local small machine shop.

I have drilled a 2 inch hole through a 5 inch s/s block - took 20mins with a speed/feed control piller drill (9foot tall floor standing drill).

they might do it for free if you sweet talk!

alan36

431 posts

185 months

Friday 5th February 2010
quotequote all
I used masonary drill bits for stainless and they worked a treat. I think they absorb the heat a bit more.

Big Al.

68,925 posts

259 months

Saturday 6th February 2010
quotequote all
Never used a masonry drill to drill St/St can see that working personally as the drill point is not ground to cut but more to bludgeon it's way through brick.

Spent my 5 year apprenticeship drilling stainless, nimonic, steels and titanium. As already said here HSS drills relatively slow speed in comparison to ally, you will need to increase speed the smaller the drill gets. Ideally centre punch the hole, start drill & be quite forceful with the feed pressure until the drill starts to bite/cut, again as already said if you don't "attack" the steel it will glaze and work harden.

Have a quick read though this, it will explain a little better it may also be a little OTT but the read will help you understand the material.

http://www.bssa.org.uk/topics.php?article=194

HTH