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What kind of drill bits for metal?

What kind of metal?

Normal high-speed bits will do fine for most steel/iron/aluminum projects, but titanium bits last longer.
 
High speed is fine for most jobs. Titanium is better, but more costly. And if you need to drill through hardened steel, you need solid carbide bits (these are not the same as carbide bits intended for masonry)
 
Normal steel/aluminum can be done with regular "jobber" drill bits. 118 degree 2 flute carbide tip. If you don't know what you're doing, though, you can definitely dull your bits. Remember to drill a pilot hole first, ~1/8" is a good size to start. And low speed/high pressure is better, until you are almost through, then you need very light pressure and higher speeds to prevent the burr from catching in the flutes and wrenching the drill around (or the part if using a drill press). And the larger the bit, the slower you need to go.
 
BoomerD said:
What kind of metal?

Normal high-speed bits will do fine for most steel/iron/aluminum projects, but titanium bits last longer.
Click to expand...

so just look for 'hi speed' on the packaging?

what would the packaging say if the bits were meant only for plastic/wood drilling?
 
cobalt 135 degree for cast iron, stainless steel

118 deg HSS is a fairly good general purpose, TiN (gold) increases lifetime
 
Any twist drill can do wood, but there are special spade or auger bits for very large wood holes. Then there are Forstner bits for wood that leave a flat bottom when you don't want to go all the through, like in furniture building where a dowel goes into, but not thru the other side. For plastic, there is a special type of twist drill bit with 90 degrees flutes so it won' t chip or crack the plastic.

http://www.rplastics.com/plasticdrill.html

http://www.diydata.com/tool/drillbits/drillbits.php

http://www.lowes.com/lowes/lkn?actio...DrlBtsBul.html
 
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Triumph said:
Normal steel/aluminum can be done with regular "jobber" drill bits. 118 degree 2 flute carbide tip. If you don't know what you're doing, though, you can definitely dull your bits. Remember to drill a pilot hole first, ~1/8" is a good size to start. And low speed/high pressure is better, until you are almost through, then you need very light pressure and higher speeds to prevent the burr from catching in the flutes and wrenching the drill around (or the part if using a drill press). And the larger the bit, the slower you need to go.
Click to expand...

This, and remember to use LOTS of lubrication; WD40, 3in1, ect.
 
So um.....still not answered, what kind of metal is it that you're trying to drill into?
 
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I use cobalt for all metals for continuous use, high speed for wood and for an odd hole or 2 on metal (less than 1/2 diameter).

One of my favorite bit is high speed multi bits that save me the hassle of carrying a dozen bits.

For holes that is greater than 1/2 up to 4" on wood, I prefer 1-5 tooth carbide hole saws. I detest forstner bits because they are useless for highspeed on wood however they work well on a low speed/high torque.

Carbide drill bits work well for small holes on concretes up to 1 1/4", while diamond tip or diamond hole/core bits almost is a must for tiles & glass. Wet saw with diamond core bits For holes that is 1" or greater.

PS. Do not lend out your cobalt bits because most idiot would find a way to break your bit.

The largest hole that I have seen cored in action was 48" holes (and it would have been cheaper if they just chipped out the 18" wall with a jack hammer). A cool $4000 for 2 holes....what a waste of money
 
bruceb said:
Any twist drill can do wood, but there are special spade or auger bits for very large wood holes. Then there are Forstner bits for wood that leave a flat bottom when you don't want to go all the through, like in furniture building where a dowel goes into, but not thru the other side. For plastic, there is a special type of twist drill bit with 90 degrees flutes so it won' t chip or crack the plastic.

http://www.rplastics.com/plasticdrill.html

http://www.diydata.com/tool/drillbits/drillbits.php

http://www.lowes.com/lowes/lkn?actio...DrlBtsBul.html
Click to expand...

You mean very large holes as in less than 1 1/2 spade bit because handling the drill become and issue at greater size (I once had to make due with a 2" space bit on a hand drill and it was an experience that I wouldn't want to repeat). Auger bits work well for low speed high torque drills such as hand drill but it is dangerous to drill deep holes in wood that it greater than 1", because the tool with man handle you.
 
Spade bits are typically used by electrician and plumber and run from 1/2 to up to 1 inch or so for most of those jobs. The auger bit you might want if you are going thru double 2 x 4 top plates or thru thick lumber. And yes, you will get some torque with them. That is why a good heavy duty, low speed drill, with a D handle and side handle are nice to have. I have a Rockwell straight 1/2 Hammer / Regular drill and also a Rockwell right angle 1/ 2 drill
 
bruceb said:
Spade bits are typically used by electrician and plumber and run from 1/2 to up to 1 inch or so for most of those jobs. The auger bit you might want if you are going thru double 2 x 4 top plates or thru thick lumber. And yes, you will get some torque with them. That is why a good heavy duty, low speed drill, with a D handle and side handle are nice to have. I have a Rockwell straight 1/2 Hammer / Regular drill and also a Rockwell right angle 1/ 2 drill
Click to expand...
<--- plumber and the 800 or so plumbers/fitters that are around me rarely use spade bit unless there aren't other choice. Auger bit on a hole hawg is the way to go or spiral bits, and the 100s of electricians that I have seen prefer spiral bits.
 
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Very true, but the auger bits cost a lot more than a spade bit. It comes down to a personal preference. Up to 3/4 inch I would use the spade bit. After that move on to the auger.
 
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