Drill bit for drilling holes in bars?

[B_Turner]

Anyone suggest a specific drill bit (and source) for drilling 1/4 inch holes in chainsaw bars?

Mine have given up the ghost and I need to drill some more holes. I want good quality, but I don't need a full set. The bits, screw extractors, etc I've tried in the past from HD, Lowes etc were pretty poor quality.

I didn't look what I had the DP set to, but maybe it was a little too fast.

I read somewhere I should drill as slow as possible with lots of pressure until the end. Sound right?

I have no real metal working background, so I thought I'd pick people's brains a little.

 

[rupedoggy]

Some of those bars are hard. I have drillerd out a lot with a concrete bit on slow speed and lots of lube. I also had luck with a good quality center drill.
The bars seem to laugh at high speed steel bits and such. One trick an old timer taught me was to back the work with a piece of steel. A heavy steel backing seems to remove the heat as you drill and the piece doesn't get harder as you drill into it. If it gets hot, as you drill, it gets so hard no bit seems to touch it. Mike

 

[REJ2]

Try a quality cobalt bit, not a titanium coated job sold by sears. 750 rpm. REJ2

 

[TommySaw]

find a builders supply place in your area they will have the bits you need individually and use a good lube low rpm and moderate pressure.

 

[chucker]

its by far fastest and easiest to take it to a metal shop to have it done.... had to have a plow clynder drilled to 1" from 3/4" and no bit, cost of the bit was 55.00 and the shop did it for 15.00....times are tough, and if your not planing on using this bit or bits often then this is the way to go....

 

[7sleeper]

try a quality cobalt bit, not a titanium coated job sold by sears. 750 rpm. Rej2

+1!

7

 

[Metals406]

http://www.artu.com/drillbits.htm

They can be bought all over the country. . . Watch the video of the bit drilling through a file.

 

[ironman_gq]

Ive got some bits from Minnesota Twist Drill that can drill through some hard stuff like old leaf springs. very flexible too so they dont snap off like a lot of other bits do

 

[Dan_IN_MN]

http://www.artu.com/drillbits.htm

They can be bought all over the country. . . Watch the video of the bit drilling through a file.

WOW! Those are some bits! It's worth checking out the vids!

Dan

 

[mtngun]

Some bars are harder than others. I haven't had much luck with either HSS or cobalt drill bits. I use a center cutting carbide end mill. You can get them from a machinist supply like Enco.

 

[Metals406]

WOW! Those are some bits! It's worth checking out the vids!

Dan

I called the company about a month ago, and talked with a lady there for a long time.

Their bits are pretty sweet for drilling hard steel.

 

[alderman]

Quick question. Just curious as to what the holes are for?

 

[wigglesworth]

Quick question. Just curious as to what the holes are for?

:agree2:

 

[B_Turner]

I called the company about a month ago, and talked with a lady there for a long time.

Their bits are pretty sweet for drilling hard steel.

They seem a bit too good to be true, but I am going to keep my eye out for them.

Thanks.

I tried resharpending my HS bit on my bench grinder which I have luck with sometimes, but I typically get too thin an included angle on the edge and the bit dulls too fast.

 

[djmercer1]

i drilled a stihl bar with generic cobalt bits from canadian tire....slow and easy with losts of grove....

b_tunrner:
like you i can sharpen a hss bit on the grinder fo rlarger sizes, i tried the drill doctor and it was ok, not great...when i sharpen bit i generally relegate them to wood, or soft steel now...

 

[Metals406]

They seem a bit too good to be true, but I am going to keep my eye out for them.

Thanks.

I tried resharpending my HS bit on my bench grinder which I have luck with sometimes, but I typically get too thin an included angle on the edge and the bit dulls too fast.

I thought the same thing, "These are too good to be true". . . So that's why I called them. The lady knew her metallurgy, and was no slouch on drill bits and drilling.

I believe they guarantee their product too?

They are available at True Value and Ace stores, as well as many others; she said if they don't stock them, they can order them for you.

The gal said their bits don't actually "drill" out the material. . . More of a grinding thing.

 

[CM76]

Solid carbide drills work well in anything that normal drills - HSS and Cobalt are struggling with. They are expensive but will handle any drilling application (within reason) when used correctly.

Regards,

Chris.

 

[wigglesworth]

If you have a drill press, just pick up a carbide end mill in the size you need and have at it.

 

[sachsmo]

Solid carbide drills work well in anything that normal drills - HSS and Cobalt are struggling with. They are expensive but will handle any drilling application (within reason) when used correctly.

Regards,

Chris.

Used correctly is key, Carbide is hard, so inherently brittle.

Don't rush the drill and be careful at breakthrough.

I use a center cutting Carbide end mill on mine.

Super simple for me as we have loads of them at work.

 

[Zippymbr]

Do you have a drill press? Drilling such a large hole through hardened steel by had is not the best idea. If so I would use smaller bits and then step it up to a larger bit. I drill alot of holes in mild steel and stainless. Good bits cost more and need to be used at a lower speed with some lube to drill through. I would goto a local industrial supply or a welding supply and buy some hardened bits there.