Twist Bits For Steel2

In this video I want to talk to you about twist bits for drilling metal

A twist bit is what you see here. It gets its name because it's kind of twisty

A little bit of a barber pole thing going on there. These bits cut with this

edge and this edge. So as it's rotating, the angle and the sharpness of

that edge digs into the metal and brings up curls of metal and that's how the

hole is created. Now the thing to understand is if you're drilling steel

which is a fairly hard metal, even mild steel is fairly hard, you're going to

need better than average twist bits. Now the normal sort of twist bit is what

they call a high-speed steel bit and it might look something like this. Just kind

of an ordinary black bit and that's going to work okay but it's not going to

last that long when you're drilling steel. What you want is one of two

improved varieties. This set and this set here are both what they call

titanium bits. So notice the gold color. The titanium refers to that

element that's been introduced into the metal that makes it harder and tougher

and they can last a tremendous amount of time when you're drilling into steel

They work really well. It's going to cost more but really there's no option. You do

need to get the titanium or the cobalt. You can see here this is some

replacement bits because even these bits, they do break from time to time

especially the smaller ones and it's important to keep your drill case

fully stocked because when you want a bit of a certain size you want it to be

there. I have broken my 1 16th inch bit as you can see here so I need to replace

that. Before I go any further I want to tell you about this box. This is called a

drill index and the reason it's called that is because there's a particular

spot for each size of bit and you can see the bits increase in size by 1 64th

of an inch. So here we have the 1 8th size and the next one up is 9 64ths

1 8th is 8 64ths but you can boil that down. Just remember your elementary

math. 1 64th of an inch all the way up from 1 16th here to half inch in diameter

at this at the side of things. Now another kind of metallurgy that works

well for steel is cobalt. Now this is not a twist bit. This is a step bit and I

discuss this amazing tool elsewhere in the course but keep your eye out for

cobalt because you can get twist bits in the cobalt style and you're going to get

lots of lots of life from that and it's really cobalt or titanium it's the only

kind of twist bits you want. Don't bother fooling around with anything else and

it's not just the bits you need. Not just the bits in the drill press or the

handheld drill. You also need cutting oil. I mean you can get away with it. You can

drill without any sort of oil but your bits are going to last much less time

and it's important not to use just any kind of oil. This is dark thread cutting

oil so it's a kind of a cutting oil. It's marketed for cutting threads on things

but it works just as well for drilling and steel. So that's the setup. You don't

necessarily need to get an index that's quite this fine. If you want to

economize a bit this sort of a case works fine and in fact I would argue

that it's really it's really the small bits you're going to use. Maybe up to a

quarter of an inch or maybe 5 16ths. These will get the most use because once you

get into the bigger sizes it makes a lot of sense to use a step bit which I've

shown in other videos that are part of the course. So that's the scoop. That's

what you need to do to equip yourself properly for drilling and steel