# Drill bits



## erics37 (May 7, 2009)

If I'm drilling through steel I just go to Fastenal and load up on cheapies out of the bulk bin.


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## wcord (Jan 23, 2011)

We normally use self-tapping sheet metal screws.
Just make sure the drill head is long enough to drill all the way thru before the screw hits the threads
They are relatively pricy but a labour saver


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## bubb_tubbs (Apr 15, 2012)

wcord said:


> We normally use self-tapping sheet metal screws.
> Just make sure the drill head is long enough to drill all the way thru before the screw hits the threads
> They are relatively pricy but a labour saver


In this instance we didn't thread the holes, just drilled it out for 1/2" and put 3/8 bolts through.

I do have a full set of drill-taps from Fastenal but they're expensive and I'm not using them for company stuff.


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## jimmy21 (Mar 31, 2012)

Why not get a drill doctor and recycle them?


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## wcord (Jan 23, 2011)

bubb_tubbs said:


> In this instance we didn't thread the holes, just drilled it out for 1/2" and put 3/8 bolts through.
> 
> I do have a full set of drill-taps from Fastenal but they're expensive and I'm not using them for company stuff.


I'm not talking about tapping the holes.
These are what we use. No fumbling with nuts etc.


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## John (Jan 22, 2007)

bubb_tubbs said:


> Anybody have a preference as far as a good blend of durability and affordability go?
> 
> I had a job mounting battery backups on 3/8 steel I-beams and burned up a decent portion of my throwaway cheapies.


What are you using to drill with?
Try pre drilling with a 3/16" bit, then the 1/2".
If you are doing a lot, how about trying a mag drill.....rent or buy. Your bits will last a lot longer and you will will be able drill a lot more holes in a shorter amount of time.......labor savings. :thumbup:


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## bubb_tubbs (Apr 15, 2012)

wcord said:


> I'm not talking about tapping the holes.
> These are what we use. No fumbling with nuts etc.


I know what you were referring to.

The customer specified bolts - no teck screws were permitted because the rear could be seen.




John said:


> What are you using to drill with?
> Try pre drilling with a 3/16" bit, then the 1/2".
> If you are doing a lot, how about trying a mag drill.....rent or buy. Your bits will last a lot longer and you will will be able drill a lot more holes in a shorter amount of time.......labor savings. :thumbup:


Tapped with centre punch, piloted with oiled 1/4" bit, drilled out with oiled 1/2" bit. 

I'd love a mag drill but I don't control the ordering. You'd have to convince the owner: I'm talking about personal drill bits here.


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## sparky970 (Mar 19, 2008)

I'd use a punch if there's a lot of holes


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## farlsincharge (Dec 31, 2010)

Drill doctor. They are always on sale at crappy tire for $100. They come with a spare grinding wheel. I use mine ALL the time.

I have tried titanium coated (joke) and cobalt bits. In the end I find I am way further ahead with a decent HSS bit and sharpening.


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## bubb_tubbs (Apr 15, 2012)

How well does that drill doctor work?


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## 8V71 (Dec 23, 2011)

Big holes in thick metal so not too many options with your limitations. You could try something like a Rotobroach but they are expensive. Maybe a good quality step drill? Slow RPM, heavy feed, and oil are your friends.


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## farlsincharge (Dec 31, 2010)

bubb_tubbs said:


> How well does that drill doctor work?


It works really well from 3/16 to 1/2 inch. It puts a shallower angle on the cutting edge than factory so the first sharpening takes a bit longer.
A first sharpen or major damage takes about 20 seconds to do.

As has been said, low RPM and PRESSURE are key to not burning bits in thick steel. Think how long a bit lasts in a drill press compared to a hand drill.


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## Cujo (Feb 4, 2012)

cutting oil really really helps if your willing to do the hassle and its feasible in the location you will be working.


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## bubb_tubbs (Apr 15, 2012)

I generally pilot on high through anything but stainless, but switch to low speed with oiled larger bits because it saves the tips and tends to chew through easier with the added torque.


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## B4T (Feb 10, 2009)

I always buy the "gold" bits in HD for drilling..

IMO.. it is easier starting out with a 1/8 bit for first hole.. switch to 1/4 and then switch to 3/8.. and to 1/2 if needed..

On a nice slow speed you can see the bit cutting the metal into "springs"..

I have a drill doctor also that I use to clean up used bits twice a year..


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## thoenew (Jan 17, 2012)

DeWalt's Pilot Point bits work rather well.


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## chewy (May 9, 2010)

I just buy an index I like then replace bits as they dull and break, I save them all for when I eventually buy a drill doctor. 

I dont do pilot bits when Im drilling, I use a centre punch and get the speed and pressure just right so the steel peels like an apple. I normally use spit when drilling to cool the bits down if nobodys watching.


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## jimmy21 (Mar 31, 2012)

chewy said:


> I just buy an index I like then replace bits as they dull and break, I save them all for when I eventually buy a drill doctor.
> 
> I dont do pilot bits when Im drilling, I use a centre punch and get the speed and pressure just right so the steel peels like an apple. I normally use spit when drilling to cool the bits down if nobodys watching.


You must have a lot of spit, it might cool it down a little, but spit is only good for lubricating one thing :laughing:


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## bubb_tubbs (Apr 15, 2012)

thoenew said:


> DeWalt's Pilot Point bits work rather well.


I've had great success with those as well.

Does the brad point tip impair its ability to be resharpened?


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## Amish Electrician (Jan 2, 2010)

Your first concern is the drill point - you want 'split-point' bits. When you look at the bit from the end, you see something like a 'bow tie,' rather than the "S" you see on an ordinary bit.

The next thing you need is some cutting oil. I find the foaming stuff from a spray can to work best for our situations. Carry a rag and wipeup your mess.

"Feed and speed" matters. Spin slow and push hard.

Brands? The DeWalt pilot points are very good. The bits sold by parts houses - often Triumph or Vermont American - are quite good. 

I've had better luck with HSS bits than with the more expensive Cobalt bits. The cobalt bits may be 'better' bits, but they are also easier to break.

As for the self-tapping screws .... you need the drill point to be somewhat longer than the thickness of the metal you're drilling, or you'll break them off in the hole. I tend to use a 1/8 bit for a pilot hole, than finish the hole with one of those screws.

Center-punching your holes is a help; look for a substantial spring-loaded punch. No hammer needed!


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## Bbsound (Dec 16, 2011)

bubb_tubbs said:


> I know what you were referring to.
> 
> The customer specified bolts - no teck screws were permitted because the rear could be seen.
> 
> ...


Your company needs to be buying consumables like bits, hole saws, flashlight batteries, etc.


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## Aegis (Mar 18, 2011)

We use tech screw but with the longer tap. The cutting threads of the tech screw has to be as long as the steel is thick otherwise the head blows off with my impact drill lol


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## chewy (May 9, 2010)

Amish Electrician said:


> Your first concern is the drill point - you want 'split-point' bits. When you look at the bit from the end, you see something like a 'bow tie,' rather than the "S" you see on an ordinary bit.
> 
> The next thing you need is some cutting oil. I find the foaming stuff from a spray can to work best for our situations. Carry a rag and wipeup your mess.
> 
> ...


A self drilling tek makes a good centre punch, automatic centre punches go for about $150 to $200 here so Im cool with the hammer method.


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## Amish Electrician (Jan 2, 2010)

Balderdash! A center punch- not a hole punch!

It's a tool that fits in your pocket, about 1/2" diameter and maybe 5" long. The really nich ones have strong springs and carbide points. A common manufacturer is "General."

To use, you place the point where you want the hole's center to be, push on it until it makes a snapping sound, and -viola!- there's a little dimple in the steel to catch the drill bit.


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## chewy (May 9, 2010)

Yeah I know what you mean but they are really expensive for decent ones like Facom and Starett over here.


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## Wirenuting (Sep 12, 2010)

Amish Electrician said:


> Balderdash! A center punch- not a hole punch!
> 
> It's a tool that fits in your pocket, about 1/2" diameter and maybe 5" long. The really nich ones have strong springs and carbide points. A common manufacturer is "General."
> 
> To use, you place the point where you want the hole's center to be, push on it until it makes a snapping sound, and -viola!- there's a little dimple in the steel to catch the drill bit.


I carry one of them and use it all the time.

Now Chewy is down-under. You could get rich shipping a few to him at Hmmm,, $45 a piece. 
LoL


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## bubb_tubbs (Apr 15, 2012)

Amish Electrician said:


> Balderdash! A center punch- not a hole punch!
> 
> It's a tool that fits in your pocket, about 1/2" diameter and maybe 5" long. The really nich ones have strong springs and carbide points. A common manufacturer is "General."
> 
> To use, you place the point where you want the hole's center to be, push on it until it makes a snapping sound, and -viola!- there's a little dimple in the steel to catch the drill bit.


Yeah, my spring-loaded one was only $10.

I do use oil, low speed and the centre punch though.


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## Frasbee (Apr 7, 2008)

I agree with Amish. Cobalt is more brittle and more expensive. If it catches on a large chunk, you're at a greater risk of snapping the bit.

You're better off using cheaper bits with a proper technique for the material.


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## LARMGUY (Aug 22, 2010)

I bought a set of industrial grade drill bits 5 years ago for $100 and keep them sharpened with a Drill Doctor. Haven't bought a drill bit since unless some dumbazz breaks one.


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## chewy (May 9, 2010)

Frasbee said:


> I agree with Amish. Cobalt is more brittle and more expensive. If it catches on a large chunk, you're at a greater risk of snapping the bit.
> 
> You're better off using cheaper bits with a proper technique for the material.


Cobalt bits were the only way I was able to drill through welds on the deck of my brothers ute, we were using self drilling screws but they werent cutting the mustard on the welded spots.


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## jeffmoss26 (Dec 8, 2011)

I just get bits from the tool crib at work...usually cobalt bits.


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## bubb_tubbs (Apr 15, 2012)

Tool crib - what a novel idea...

These guys won't even buy drywall anchors (lots of them use 1/4" blues in sheetrock!)


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## MechanicalDVR (Dec 29, 2007)

If you were using 3/8" bolts it seems a waste of time to drill 1/2" holes. I'd drill the proper size hole and it wouldn't be with drill bits I provide.


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## coon88 (Dec 9, 2011)

wcord said:


> I'm not talking about tapping the holes.
> These are what we use. No fumbling with nuts etc.


Those are tek point screw...try the 5 points for the harder items


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## 8V71 (Dec 23, 2011)

MechanicalDVR said:


> If you were using 3/8" bolts it seems a waste of time to drill 1/2" holes. I'd drill the proper size hole and it wouldn't be with drill bits I provide.


I was wondering why such big holes but I figured he has a reason.


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## chewy (May 9, 2010)

8V71 said:


> I was wondering why such big holes but I figured he has a reason.


No spud? :laughing:


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## bubb_tubbs (Apr 15, 2012)

1/2" because it's the size of the bit they provided.


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