Drill bits

[Lynn Sonier]

I've seen a set of drill bits advertised at woodworking shows that they demonstrate drilling through all kinds of material. Does anyone know what company sells these? Tried to enlarge a hole in a lawnmower blade today - made a little smoke is all it did.

Thanks!

[tod evans]

lynn, drill metal slooooowly. any bit should do a lawnmower blade they`re soft..02 tod

[Ken Garlock]

Lynn, wasn't that the Ginzu Drill set?:confused: It is only available on a special TV offers for $19.95 plus $83.79 shipping and handling. Call our special 900 number shown at the end of the program.:eek: Say the prices are too high, for this time only, we will throw in one barrel of Texas light sweet crude.:D

Just people helping people....

Butttt, a real answer to your problem is Bad Dog Tools (http://www.baddogtools.com/).

[Steve Clardy]

Er. Bad Dog tools? Something like that.
I bypass those booths.

[Cliff Rohrabacher]

look in your yellow pages for an industrial supply. Buy good
HSS drills.

If the blade is hardened (unlikely hardened in the center) you can tell by stroking lightly a #2 mill file across the steel. It'll feel harder than normally soft tool steel.

At the diameter you are working ( 3/4 to 1 ") you need to do a couple of things:
#1) Speed kills. RPMs shouldn't be higher 60.
#2) Oil. You gotta lube the cutting interface. Use a brush and any oil you got. No need to flood it just dab some on as you cut. I use automotive 'cause it's around. Even auto tranny fluid is better than nuthin.
#3) clamp everything. when the bit is clearing the back side it's going to try and tak the last bit of material in one bite. This will likely result in a wildly spinning workpiece unless you clamp it. That will prove very dangerous with a workpiece that's large and sharp.

Now go re-sharpen that drill bit on a sander or grinder and start over from the other side of the blade as you likely work hardned the steel on the side you smoked out.

If it seems to grab a lot when cutting grind a little flat on the face of the cutting edge to nuturalize the rake. Normally this is done for steel and copper (not steel or iron) but you may find it grabs when you already have a substantially large hole you are following. A zero rake will solve for that.

A zero rake is also great for Plexi and lexan.