Drill Bit for Frame

[marvin2]

I am doing the crown victoria IFS swap and need to drill holes in my frame. Any suggestions on the type of bit I should pick up to drill the new mounting holes?

[Joshpow]

I would buy a good quality plain bit. Just keep it cool and it should do ok. Drilled some crazy stuff at work with plain jane bits and coolant.

[goldies67]

i use the uni bit,with LOTS of drill lube! the better quality bit,the more $$ so its totally worth the cost,good luck!

[Donnie]

At least 5% cobalt & keep it cool.......worth the $$$....Donnie

[goldies67]

[marvin2]

Thanks guys!

[JG F100]

yes, try a good unibit. I cant remember the size of the hole but large drill bits are hard to find.

[elgemcdlf]

I bought mine at Ace Hardware. $26.00. I stepped up twice prior to using the final bit. I think I started with 1/4", then 3/8" then the final cut. It was fun but I was on my back doing the lowers.

[Bumpside Collector]

You can do it with just a plain high speed steel bit. Just keep the drill motor rpms low and keep the bit lubed with something and you will be ok.

[tsherry]

I have cobalt bits, and hopefully will never have to use high speed steel again. Cobalt's ****far**** faster.

[Bumpside Collector]

I have cobalt bits, and hopefully will never have to use high speed steel again. Cobalt's ****far**** faster.

Cobalt bits are nice! They get the job done a lot quicker but I have done it the hard way with the HSS bits. Slow is the way to go with them!

[averagef250]

Cobalt is HSS with cobalt added.

The problem with drilling with a hand drill isn't the drill bit, it's almost always always the user. Twist drills function on high feed, low speed. A lot of people run them WAY to fast and probably have a dull bit to start with. A HSS 1/2" drill bit with no pilot hole should poke through a mild steel frame rail in a few seconds at 500 RPM. If it doesn't it's rubbing, not cutting creating excess heat and losing it's cutting ability.

When using drill bits also keep in mind that drills don't automatically cut a round hole nor do they go straight. If you want to not burn up drill bits, get an on-location hole and not break your arm drilling do something like this-

A) put a level forklift fork under the frame rail with pressure up on the rail, clamp your mag drill to the forklift fork and pop a 1/2" hole right through the frame.

B) if you don't have a mag drill or a forklift you just have arm power and arm power can't push a 1/2" bit through steel at the minim feed required to not melt the bit. Center punch the hole, drill through the frame with an 1/8" split point bit at 800-1500 RPM, pick the biggest drill bit you have that has a web thickness less than 1/8", this will probably be around 5/16-3/8". Run that bit through at 600 or so then your 1/2" bit's web should clear fine and run that through at 500. When you're not trying to force the web of the bit through the steel the bit will feed into the material with far less force.

The tip of a drill bit doesn't cut very well, basically the poor-cutting area of a drill bit is the thickness of it's web at the end of the bit (the diamter of a drill bit gets smaller away from the tip and the web gets thicker). Split point bits cut better right on the tip, but they cost more and are much harder to sharpen. So if you push a 1/2" drill bit through steel with no pilot hole you essentially pushed a solid rod through the steel the diameter of the thickness of the web in the bit (3/16" or so).

Also, this is pretty basic, but if you don't have chips coming out of the hole the bit is rubbing, not cutting (rubbing is bad).

[Bumpside Collector]

That is a real good explanation averagef250!

[72ford350]

Cobalt is HSS with cobalt added.

The problem with drilling with a hand drill isn't the drill bit, it's almost always always the user. Twist drills function on high feed, low speed. A lot of people run them WAY to fast and probably have a dull bit to start with. A HSS 1/2" drill bit with no pilot hole should poke through a mild steel frame rail in a few seconds at 500 RPM. If it doesn't it's rubbing, not cutting creating excess heat and losing it's cutting ability.

When using drill bits also keep in mind that drills don't automatically cut a round hole nor do they go straight. If you want to not burn up drill bits, get an on-location hole and not break your arm drilling do something like this-

A) put a level forklift fork under the frame rail with pressure up on the rail, clamp your mag drill to the forklift fork and pop a 1/2" hole right through the frame.

B) if you don't have a mag drill or a forklift you just have arm power and arm power can't push a 1/2" bit through steel at the minim feed required to not melt the bit. Center punch the hole, drill through the frame with an 1/8" split point bit at 800-1500 RPM, pick the biggest drill bit you have that has a web thickness less than 1/8", this will probably be around 5/16-3/8". Run that bit through at 600 or so then your 1/2" bit's web should clear fine and run that through at 500. When you're not trying to force the web of the bit through the steel the bit will feed into the material with far less force.

The tip of a drill bit doesn't cut very well, basically the poor-cutting area of a drill bit is the thickness of it's web at the end of the bit (the diamter of a drill bit gets smaller away from the tip and the web gets thicker). Split point bits cut better right on the tip, but they cost more and are much harder to sharpen. So if you push a 1/2" drill bit through steel with no pilot hole you essentially pushed a solid rod through the steel the diameter of the thickness of the web in the bit (3/16" or so).

Also, this is pretty basic, but if you don't have chips coming out of the hole the bit is rubbing, not cutting (rubbing is bad).

Average250 has got it absolutly right.

On variable speed drills it is dificult to guess your rpm with good accuracy. I have always been told that the lager drills 1/2 and above if you cannot see the flutes of the drill as it turns odds are you are turning it too fast. This is what I was told and I have never burned up a bit using that method coupled with lots of drill lube.