that-guy

i have a set of Cobalt drill bits and they just spin and heat up with stainless. what is the best drill bit material to use with stainless?

racebum

drill i small pilot hole first and use oil while you're drilling through. cobalt will go through without issue. are you starting with a 1/2" bit or something?

russianvr4

youre most likely not doing it right.
keep the drill speed slow and use coolant for stainless.

RickyLee53

Drill speed low, pressure high and keep it cool as above.

HickamHatch

Stainless loves to be lubbed with oil before you drill her

Organization

u have to go slow with lots of pressure and lube for regular drill bits or they will burn up so you have to keep them cool

u need good drill bits like titanium tip bits, lubrication is a plus i like a mix 20-80 water oil, water cools it while oil lubes it

Or even better you can get some carbide bits (problem solved) i drill stainless gutters all day at my electric company

postman

the cobalts will work if done right. super slow and plenty of lube as always.

that-guy

hmmmm, i was using plenty of lube, but i guess my drill speed was too high

Glen_63

Is your bit sharp?

that-guy

they are brand new. just bought them a few days ago

gamnoparts

Stainless gutters? No wonder our electric bills are so high.

Seems we have a consensus...slow, hard & wet... I will let you insert your own joke, tends to write itself. :D

Organization

lol we only use gutters on commercial buildings where it is either always in humid conditions, around chemically treated water, or boiler rooms, any where there is lasty stuff we wanna keep out that can and will eat thru mild steel

also if u got that drill bit kit from lowes then that cobalt is the name brand not qaulity but even so it should drill atleast one hole fast or slow like i said get a titanium tip drill bit set and dont look back there not expensive and you wont be breaking your back waiting for the hole to be drilled

i got to kits , a cheap drill bit kit for regular stuff and titanium tip for difficult stuff i also got the carbides for precision holes that have to be drilled out perfectly with no debur

Organization

find out also if the bits are high speed or neither

JDMCRX

iTrader: (2)

Buy some Good Cobalt bits. Those cheap bits are junk. I was struggling with cheap cobalt bits then went and bought like 4 drill bits from a good company and wow drills thru it like butter.

Drill a small hole then step it up also at a slow speen to fast and your harden the stainless.. That way your bits last for long time. Also try to use a press if you can.

Organization

then titanium bits from Home Depot and most have tips meant to center,start holes and pre drill the pilot hole already on the larger bits

unless i lost, broke, or damage a titanium bit by trying to drill a hole thru metal near a concrete wall i went to deep into them they last a long time had mines for 10 years minus a couple 3/16 bits

95ttht

iTrader: (1)

Slow is the key. Biggest mistake most people make is high speed and trying to force it. Slow, lubed, and very little force.

RickyLee53

With stainless you need pressure. If not the bit will just get warm.

Organization

yes with the usual stuff-hard,slow and lube but with the good stuff you don"t need that much pressure because it's sharper and doesn't get hot enough to weaken the bit and stays sharp, lube is a plus it helps cut the hole faster and keep the bit cooler (wd40) easy clean up

you need to know what type of bit your using to know what tech to apply, with most bits made of cheap metal (slow hard and lube)
with steal bits (slow to moderate speed, moderate pressure to hard and lube)
cobalt bits are just harder and can take a little bit more heat so slow to start hole then moderate speed to drill it out

stainless steel bits you have to put pressure and lube your basically drilling with the same material just heat treated to make it harder but it can still burn up and if you see any of the bits glow red then your bit is no good no more, you can use the wd40 to tell when your get to hot so that you can either slow down or stop spray with wd40 to cool it and proceed

titanium is hard can take lots of heat and you can go slow or fast, and if you use lube it will last almost forever

theres other types but they cost$$$

Organization

I have seen bits melt on stainless steel and snap because ss doesn't usually (dont know the correct wording) deburr like regular metal like the lil flakes it will some times make long hard flexible, sharp strings of metal that will go around your bit or worst thread into the hole instead of drilling it out that's why you have to use only the proper force or you can force to bit to shatter