BigDawgV8
|
| posted on 15/6/08 at 08:28 PM |
|
|
Drilling Stainless - Tips Please
Hi All,
Does anyone have any tips for drilling stainless steel without work hardening it and wrecking drill bits!
Lots of lube and slow speed, what else?
Any help much appreciated.
Cheers
[Edited on 15/6/08 by BigDawgV8]
|
|
|
|
|
clairetoo
|
| posted on 15/6/08 at 08:31 PM |
|
|
Lots of lube and slow speed 
Its cuz I is blond , innit
Claire xx
Will weld for food......
|
|
|
stuart_g
|
| posted on 15/6/08 at 08:40 PM |
|
|
I have found that small drill bits need to be done at speed. large drill bits done slow, both with lube. The only drill I could get to work for small
drill bits was my air drill. Battery and electric drill did not work. You also need to keep steady pressure on the drill at the same time. This was
what I found when drilling a robin hood 2b chassis but that could have been down to the stainless they used.
|
|
|
macspeedy
|
| posted on 15/6/08 at 08:43 PM |
|
|
cobalt steel drill bits, and COOLANT!
[Edited on 15/6/08 by macspeedy]
|
|
|
macspeedy
|
| posted on 15/6/08 at 08:45 PM |
|
|
COOLANT start small and TAKE YOUR TIME !!! 
|
|
|
andrew-theasby
|
| posted on 15/6/08 at 08:55 PM |
|
|
I drill a pilot hole then open up with taper reamers at work, they just push through effortlessly and last fairly well too. Dont know how much they
cost tho, i dont buy them for work.
|
|
|
Michael
|
| posted on 15/6/08 at 08:55 PM |
|
|
stuart_g is correct, with speeds and drills.
Small drill needs to be quite fast, and large drills quite slow.
Sharp drills are a must too.
I find a sign of a good drill & speed is if you get a spiral of metal of material then its a good cut, small dust (normaly from large drill) then
speed is to fast.
I haven't drilled stainless though.
[Edited on 15/6/08 by Michael]
|
|
|
MikeCapon
|
| posted on 15/6/08 at 08:57 PM |
|
|
Rocol is the best lube I have found for stainless. Another tip is to 'rest' the bit frequently.
www.shock-factory.co.uk
|
|
|
BenB
|
| posted on 15/6/08 at 09:12 PM |
|
|
Less need to "rest" the bit if you're using enough lube but certainly they cut best when cold....
|
|
|
NS Dev
|
| posted on 15/6/08 at 09:18 PM |
|
|
slow + coolant + lots of cutting pressure, whatever size drill you are using, use about 1/2 the revs you would use on mild steel.
Retro RWD is the way forward...........automotive fabrication, car restoration, sheetmetal work, engine conversion
retro car restoration and tuning
|
|
|
tegwin
|
| posted on 15/6/08 at 09:36 PM |
|
|
You need quite a wide angle cobalt stub drill..
Basically a short series HSS drill bit coated in cobalt.....will really cut through, just dont over heat the metal or it will go rock hard...
------------------------------------------------------------------------------------------------------------------------
Would the last person who leaves the country please switch off the lights and close the door!
www.verticalhorizonsmedia.tv
|
|
|
dhutch
|
| posted on 15/6/08 at 10:06 PM |
|
|
I would back up the 'slow, push hard, keep cool' routine for larger holes in stainless.
- For best obviously a pillar drill is good, but sharp/cobolt bits works too...
Daniel
|
|
|
Hellfire
|
| posted on 15/6/08 at 10:22 PM |
|
|
There are a number of recommendations when drilling stainless. Firstly - it depends upon the type. Usually it is 316... but loads more are available
304, 303 etc etc all with differeing cutting characteristics.
1. Use a good quality 5% Cobalt TiN Coated drill if you can lay your hands on one. Make sure it is correctly ground with the web thinned to 1mm max.
(This helps to reduce chisel point heat).
2. Go slow with the speed but more importantly do not allow the drill to rub. This will work harden the material and make the matter much worse. Keep
on the feed constantly and keep very cool with copious amounts of lubricant.
3. Where good safety glasses/goggles as when the drill snaps they can fly anywhere...
Good luck!
Steve
|
|
|
owelly
|
| posted on 15/6/08 at 10:58 PM |
|
|
As said but I don't agree with the start small and use slightly larger drill as you go until you get to what size you need. I find that a 3or4mm
pilot is a good start. Use a good cutting fluid or paste and keep the bit cutting. As soon as it feels as though it's not cutting. Stop and find
out why.
Then go for the big bit. Using the slightly increasing sized drills, causes them to overheat on the very ends of the cutting edges which hardens the
metal.
Go for the large, keep it cutting and use the swarf to carry the heat away from the work. If you have clouds of smoke off the lubricant. Stop. Check
the bit for sharpness. Let everything cool. Continue.
Repeat to fade.........
http://www.ppcmag.co.uk
|
|
|
hughpinder
|
| posted on 16/6/08 at 08:29 AM |
|
|
I can confirm that cobalt drills are dangerous when they snap - I was drilling a hole in a boot for a friend once and the drill snagged and shattered
- cut one finger to the bone and we had to pull the other bits out of the steel sides of the boot with pliers!
Hugh
|
|
|
