Drilling stainless steel

[farmtruc]

hey guys,

we install quite a bit of o2 bungs before the tuning process, some setups have nice stainless and other have mild steel exhaust.
our bits work great on mild steel, however, we simply cut a quick hole with the plasma for the stainless.
what drill bit are you guys using to drill through stainless? and how long are they lasting?
mine don't seem to last very long.

i buy decent and cheap bits and the better ones obviously cut better.
what's the best and strongest, longest lasting drill bit available?

i also bought a kit of those Rotobroach bits, pricey for four of them, they worked great at first, but the stainless killed them.
http://www.ohiopowertool.com/c-63-me...oach-bits.aspx

thanks,

[double047]

Drilling stainless steel can be a pain in the you know what. My maintenance guy says Winzer Shop Pros do pretty good.

It just plain sucks drilling stainless steel on a regular basis, especially the good stainless mostly because it heat-hardens more so than the milder grades.

The biggest problem is most people try to drill stainless steel with way to high of an rpm and not enough pressure.

The keys to drilling stainless steel.

-> Lower work speed.
-> Higher tool pressure.
-> Lubrication.
-> Keep the bit cool. (air stream on it or compressed air)

Possibly pilot holes would help.

[sprayedenali]

Start small ad work up in size. Keep the bit cool and slow. A uni-bit works alright. Touching get a few really nice carbide bits just for the stainless....

[bstill]

Just take it slow. Don't run the drill wide open and keep a steady feed rate(pressure). Use something to keep it lubed and cool. Stainless is a soft metal but dense too. Because of its density, it's harder to drill. I was a machinist for years and we machined a lot of stainless. So, I got kinda good at it.

[2boosted]

In my line of work we drill a lot of metals.

We test all, and the most durable to date will be the Bosch Titanium Coated Drill Bits.

Like any drill bit, if you use it wrong, you'll brake it, lose sharp or damage the drill.

Silversleeper stated the fact correct, but in our line of work, we use a cooling liquid instead of air. Is a white liquid, and we try to recycle it. For Special materials we use Relion Formula. That and a good driller, makes bits last.

[Trick1]

Drill slow
Start small
stepping up.
Keep cool
and
NEVER let the bit bounce.

Bouncing the bit off the metal will case harden the stainless.
Once that happens kiss the bits cutting edge by. And then it takes slot of pressure to get through it. Wiping out the bit.

[farmtruc]

thx for the replies!

i'll try some carbide and bosch titanium next time.

i do have the drill press on low, i'll step it down even more.


do you guys press hard on the bit , medium pressure, or light?

[2boosted]

I can Press HARD on you !!!!

Dude, you must press hard. That will make a lot of heat. Use some cooling liquid of your preference. I like relion. They sell it at Miami. Texas must make same things around !

[Trick1]

Hard enough to make a cut.
If it rotates with out cutting (bounce) it can harden it.

Even done correctly you will still wear the tool out faster then plain steel.

Stainless is great , just a pain to work with sometimes.

[Crazy Blu]

Machine shops do as kb stated too
Alum. Highest rpm
Mild steel slightly slower
Ss the slowest