Hey guys, I'm in the market for a set of nice drill bits for doing metal work. In the past I've used el cheapo bits from home depot and whatever else I had laying around from my wood working stuff.

Should I look for a titanium coating? Or full carbide bit? I'm assuming carbide will probably be the way to go, but I'm open to any suggestions.

 

Buy either cheap stuff, or mid ranged stuff. Expensive drill bits aren't worth it for the home shop guy. #1 rule for drilling....KEEP THE DRILL BIT COOL!!!!

Letting it get hot will dull it very fast....then it won't cut for ****.

oh, and turning speed is not equivalent to cutting speed on stainless. If you turn fast, it gets hot and cuts harder... bit dulls, and cuts worse as you progress.

 

engloid is right speed is key, i have made el cheapo bits work just as well as the more expensive ****. in which i mean 1/2 bit = .50 compared to pricey bit 1/2 = $10

 

I use heavy duty cobalt bits that i order for about $5-$10 each depending on size of it. Then agian i drill A LOT of holes and and a lot of stainless steel which most people refuse to cut at all.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ExploitedRacing &raquo;</TD></TR><TR><TD CLASS="quote">I use heavy duty cobalt bits that i order for about $5-$10 each depending on size of it. Then agian i drill A LOT of holes and and a lot of stainless steel which most people refuse to cut at all.</TD></TR></TABLE>
My guess is that you've got the experience to make them last. Most amateur guys think that the faster they turn the bit, the faster it will cut, and you know it's far from the truth..


A word to any guys that want to run a drill wide open: There's a reason that a good drill press or lather has variable speed. It's partially so that you can turn the tool speed down and CUT FASTER.

 

Also remember too, do not try and drill too big of a hole in one shot. If i'm drilling anything more than a 1/4" hole in 3/16 thick (steel) I start with a small pilot hole first. I ALWAYS use cutting tapping fluid when drilling anything thicker than that also (the dark smelly brown stuff) This will greatly increase bit life, as well as speed as mentioned many times above.

 

Water is very underrated for home hobby drilling also... with oil, you mainly just lubricate. With water, you can just soak it and keep it much cooler than you would with cutting oil. Granted, if it's not going to get hot, oil is good.

 

Use a slow turning speed, and lubricant. They will last well.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Engloid &raquo;</TD></TR><TR><TD CLASS="quote">
My guess is that you've got the experience to make them last. Most amateur guys think that the faster they turn the bit, the faster it will cut, and you know it's far from the truth..


A word to any guys that want to run a drill wide open: There's a reason that a good drill press or lather has variable speed. It's partially so that you can turn the tool speed down and CUT FASTER.</TD></TR></TABLE>

When drilling stainless steel i run about 350RPM, when drilling mild steel i drill at about 800RPM, I also have a flooder type coolant system.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ExploitedRacing &raquo;</TD></TR><TR><TD CLASS="quote">

When drilling stainless steel i run about 350RPM, when drilling mild steel i drill at about 800RPM, I also have a flooder type coolant system.
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And the lager the hole, the slower you turn, correct?

 

wow with ss i turn usually 170 depending on size of the hole. slower than molasses but its cuts so nice...

 

what drill are you guys using, i'm looking for one with variable speed dial for adjusting the speed....

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Engloid &raquo;</TD></TR><TR><TD CLASS="quote">
And the lager the hole, the slower you turn, correct?
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No i speed up. *Sarcasim*

Of course i slow it down for larger, thats what i do for 3/8" drill bit, usually do the same for 11/32 (very comon size i use)

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ExploitedRacing &raquo;</TD></TR><TR><TD CLASS="quote">

No i speed up. *Sarcasim*

Of course i slow it down for larger, thats what i do for 3/8" drill bit, usually do the same for 11/32 (very comon size i use)

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Just wanted to make sure we DRILL it into the heads of the guys that think faster is better

 

But there is a point on smaller bits that you can turn too slow right? I was assuming so because I was drilling some 4-5mm holes in 10g mild steel and my holes came out kind of ovaled. I know the work wasn't moving and I was using very light pressure so I sped the drill up a bit (sucks on a cheap benchtop drill press) and they looked much better. So is it correct that you can go too slow on small holes (under 8mm)?

Also anyone have good luck with the drill doctor? I've never used one and thought of picking one of the smaller models to try but dont want to waste the money if they dont work for ****.

 

the ovaling is because the material is so thin, when I drill sheet metal(anything under 1/8) I grind my bits similar to a spot weld tool. I cuts like a holesaw, a point in the center to stabilize and an edge to cut just on the outside. they make a nice round hole every time. I don't know about the drill doctor but ask "ek9t" I think he has one. I have a big heavy duty sharpener and would never sell it. I the best thing since sliced bread.

 

i have the adjustable speed 20" floor press from wholesale tool, its an import but its a 12 speed, and it goes as low as 140 and as high as 3600 or somehting like that. i love it. ****** is like 350 lbs lol. i have drilled thru 3/4 like nothing with it.

 

I've used the drill doctor. They work well when used right, and they're not too difficult to use....

but they are pretty slow to grind a good edge. They don't have a lot of torque, so you have to grind slow.

I prefer to grind them by hand on a bench grinder, but that takes practice to learn to do that.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Engloid &raquo;</TD></TR><TR><TD CLASS="quote">I've used the drill doctor. They work well when used right, and they're not too difficult to use....

but they are pretty slow to grind a good edge. They don't have a lot of torque, so you have to grind slow.

I prefer to grind them by hand on a bench grinder, but that takes practice to learn to do that.</TD></TR></TABLE>
yea i am not too good at grinding drill bits. My dad is very good, but that does me no good when i actually have to get some work done and he is no where to be found.