> seen people using oil on drill bits
Why do they do this? I would think it would bite into the metal better without oil.
I’ve also seen people spraying this white oil/water concoction… so it rusts faster? None of this makes any sense.
t. woodworker
most drill bits lose their useful qualities (sharpness, hardness, compressive strength) when you get them too hot. Oil and cutting fluid mixtures both help inhibit corrosion from exposure to oxygen and cool the cutting tool down. In some cases it can also help clear chips from the cutting area if enough is used.
Lubricity.
Drills dont need help biting into metal. They need help mitigating the immense amount of heat they create.
When you drill, you create huge friction while you cut a metal chip/shaving.
Chip soaks up heat, flies out of hole and removes the heat from drill bit and work piece. The whole process done correctly, feeding hard enough and cutting big enough chips keeps the drill from overheating.
This is why everyone says feed hard and go slow when hand drilling metal. The people who blast their hand drills at 2100RPM and have a little pile of sand under their hole destroy every drill bit they touch.
When you increase lubricity with cutting fluid, there is far less friction during the cut, creating less heat to remove.
The oil also lubricates and allows the hot chips to move up the flutes and out of the hole better.
Better tool life, better finish, no reason not to use it.
Its really useful for materials like aluminum which loves to adhere and stick to drill flutes
Thanks, makes sense. I don’t think wood is going to get as hot. Someone should invent carbide drill bits, it’s on every tablesaw blade I have, and every router bit.
>t. woodworker
so you're telling me you've never waxed your cutting tools? next time you use a handsaw, try rubbing wax on both sides of it first and then you'll understand
Yeah, i wax/oil my old saws, i have a couple that have teflon coating, never wax those. Never wax my table saw blades. Never wax my japanese saws.
Wood definitely likes woodchips to be evacuated out of the hole when drilling, but its not as critical of a situation.
> Someone should invent carbide drill bits,
They exist already. Carbide is very brittle and requires precision. If your speeds or feeds are wrong, or you put axial pressure or anything like that, they will just shatter.
The majority of people just dont really need them, and if you use them outside of a CNC you will just blow up your $50 drill bit. HSS works fine on steel, Cobalt works fine for hardened steel.
Carbide just lasts a lot longer with hardened work, but it has to be under perfectly ideal situations.
They sell HSS shanked, Carbide tipped drills but they still arent super cheap and are kind of rare.
https://www.amazon.com/Jobber-Carbide-Tipped-Standard-50425/dp/B00PM4TUSC/
Solid carbide will cost double that.
11 months ago
Anonymous
> carbide drill bits
Wish I knew that beforehand, sharpening drill bits is a PITA. Just buy one, and you’re good for the next 25 years or so.
Lubricity.
Drills dont need help biting into metal. They need help mitigating the immense amount of heat they create.
When you drill, you create huge friction while you cut a metal chip/shaving.
Chip soaks up heat, flies out of hole and removes the heat from drill bit and work piece. The whole process done correctly, feeding hard enough and cutting big enough chips keeps the drill from overheating.
This is why everyone says feed hard and go slow when hand drilling metal. The people who blast their hand drills at 2100RPM and have a little pile of sand under their hole destroy every drill bit they touch.
When you increase lubricity with cutting fluid, there is far less friction during the cut, creating less heat to remove.
The oil also lubricates and allows the hot chips to move up the flutes and out of the hole better.
Better tool life, better finish, no reason not to use it.
Its really useful for materials like aluminum which loves to adhere and stick to drill flutes
>t. woodworker
so you're telling me you've never waxed your cutting tools? next time you use a handsaw, try rubbing wax on both sides of it first and then you'll understand
I'm no metalworker, but I've seen more than a few times that you need to step up through a few bits at that size because the drill's core can't handle all the pressure of pure drive through most material.
You got it. Cobalt for drilling steel.
Old school HSS (Dormer) is good too. Nothing worse than cheapo "tatanium coated" bits from a hardware store.
Hex shank is a big red flag you have garbage bits.
>is it a optical illusion?
No. A bit with decent hardening will often shear cleanly like that when it gets bound. Sometimes they fully frag. Soft bit will sometimes straighten the flute, causing enough of a braking action to stall the drill without necessarily breaking the bit.
suscribed
>no lube
>just the tip
you can literally see the sheen of leftover cutting oil
who called themselves a machnist you moron gayet
How did it happen, anon?
Pathetically bad user error
> seen people using oil on drill bits
Why do they do this? I would think it would bite into the metal better without oil.
I’ve also seen people spraying this white oil/water concoction… so it rusts faster? None of this makes any sense.
t. woodworker
most drill bits lose their useful qualities (sharpness, hardness, compressive strength) when you get them too hot. Oil and cutting fluid mixtures both help inhibit corrosion from exposure to oxygen and cool the cutting tool down. In some cases it can also help clear chips from the cutting area if enough is used.
Thanks, makes sense. I don’t think wood is going to get as hot. Someone should invent carbide drill bits, it’s on every tablesaw blade I have, and every router bit.
Yeah, i wax/oil my old saws, i have a couple that have teflon coating, never wax those. Never wax my table saw blades. Never wax my japanese saws.
Wood definitely likes woodchips to be evacuated out of the hole when drilling, but its not as critical of a situation.
> Someone should invent carbide drill bits,
They exist already. Carbide is very brittle and requires precision. If your speeds or feeds are wrong, or you put axial pressure or anything like that, they will just shatter.
The majority of people just dont really need them, and if you use them outside of a CNC you will just blow up your $50 drill bit. HSS works fine on steel, Cobalt works fine for hardened steel.
Carbide just lasts a lot longer with hardened work, but it has to be under perfectly ideal situations.
They sell HSS shanked, Carbide tipped drills but they still arent super cheap and are kind of rare.
https://www.amazon.com/Jobber-Carbide-Tipped-Standard-50425/dp/B00PM4TUSC/
Solid carbide will cost double that.
> carbide drill bits
Wish I knew that beforehand, sharpening drill bits is a PITA. Just buy one, and you’re good for the next 25 years or so.
Lubricity.
Drills dont need help biting into metal. They need help mitigating the immense amount of heat they create.
When you drill, you create huge friction while you cut a metal chip/shaving.
Chip soaks up heat, flies out of hole and removes the heat from drill bit and work piece. The whole process done correctly, feeding hard enough and cutting big enough chips keeps the drill from overheating.
This is why everyone says feed hard and go slow when hand drilling metal. The people who blast their hand drills at 2100RPM and have a little pile of sand under their hole destroy every drill bit they touch.
When you increase lubricity with cutting fluid, there is far less friction during the cut, creating less heat to remove.
The oil also lubricates and allows the hot chips to move up the flutes and out of the hole better.
Better tool life, better finish, no reason not to use it.
Its really useful for materials like aluminum which loves to adhere and stick to drill flutes
>t. woodworker
so you're telling me you've never waxed your cutting tools? next time you use a handsaw, try rubbing wax on both sides of it first and then you'll understand
>I would think it would bite into the metal better without oil.
Correct, but that's exactly what you DON'T want it to do.
The heat is the issue. You can actually make the surface you're trying to drill thru even harder by NOT using oil and overheating it.
Actually the m42 Cobalt bits are what you want. The ones from Bosch have proven to be reliable.
>Those tiny metal flakes, and the light misting of some type of oil, just screams newb.
TRUE
Cobalt is def the best if you resharpen
perfect example of a shitty machinist
that's a nothing burger - breaking tiny taps in blind holes is orders of magnitude worse. anything below like #10 is always nerve wracking.
I came here to post this. It's a non-issue.
I'm no metalworker, but I've seen more than a few times that you need to step up through a few bits at that size because the drill's core can't handle all the pressure of pure drive through most material.
You have more than enough to grab, breaking taps into shit sucks
Thank you for reminding me, a 15pc set of titanium Milwaukee drill bits is on flash sale at HD
Piss on those. I buy five or ten packs of cobalt alloy bits online for any size I need. The durability makes them cheaper per hole than lesser bits.
It was $10 which I thought was completely worth it
You got it. Cobalt for drilling steel.
Old school HSS (Dormer) is good too. Nothing worse than cheapo "tatanium coated" bits from a hardware store.
Hex shank is a big red flag you have garbage bits.
>too dumb to preserve tool life
>buys far more brittle bits to try and compensate
this image is really fricking me up, is it a optical illusion? I'm having a stroke from just looking at it.
>is it a optical illusion?
No. A bit with decent hardening will often shear cleanly like that when it gets bound. Sometimes they fully frag. Soft bit will sometimes straighten the flute, causing enough of a braking action to stall the drill without necessarily breaking the bit.
Worst part about this is that it was done on a drill press where you can absolutely control the speed, pressure, angle, etc.
Those tiny metal flakes, and the light misting of some type of oil, just screams newb.
It could have been prevented.
Next time, don't buy chinesium bits.
Stop using harbor freight drill bits. Maybe get someone to show you the right way to do that.