drill point angle ? drill bit recommendations

[docbdj]

I use high carbon steels for my knives 1080 and 5160, etc

going to order some drill bits from MSCdirect - or whoever else you guys recommend

thinking -
jobber length, 1/8,1/4,3/16, 3/8
cobalt for non hardened steels
titanium nitride for handle materials
titanium aluminum nitride - for steel

my question is what drill point angle do most recommend to be most efficient / effective ???

any other recommendations ?

thanks

 

[Lieblad]

I typically buy jobber or stubby HSS 135° Usually shiny finish or TiN coated, not too fussy about that. Blacks too,
Said that I find 118° are perfectly servicable.
One thing I always get are split point. Unless around .5” or so. I will normally pilot for holes larger than that.

 

[Rhinoknives1]

I drill most of the time after HT . Cause my blades are water jet cut and I have them HTed before I bevel grind & taper the tangs after. Sometimes I need to add in a handle pin hole—————I use Carbide bits no longer than about 4” OaL with a 90-118 degree edge ..

 

[Busto]

A Tap and Drill wall chart for sizes is a must in any shop.

 

[Sam Dean]

Don't waste your money on coated drill bits. They don't really add much life, and if you resharpen the bits the coating is gone anyway.

Instead, spend your money on high quality material from a good brand. I like to use screw machine length (stubby) whenever possible because they're stronger and straighter. Viking/Norseman drills are a personal favorite of mine (made in Minnesota)

Type of material being cut will dictate point angle. Personally, I go with 118° for pretty much everything. If I was in a high volume production setting, drilling thousands of holes daily, then I'd care more.

Here's a handy chart:

 

[Nathan the Machinist]

I've tried everything and I've gone back to old school 118 degree, no split. A good quality drill will cut thousands of holes if your parameters are good. I use 118 degree regular point, bright finish, Chicago Latrobe screw machine length, although jobber length would work just as well.

My process is to spot and then drill (then interpolate and ream for accuracy so scales and fixturing can be snug fits), no pecks, 900 RPM and 4.5 inches per minute (for ~ 1/4"), flood coolant. A typical run is 200 blades and a typical blade gets 6-8 holes (pin holes, fixturing hole, clearing out for plunge for skeletonizing and lanyard hole). That's well over a thousand holes in 3V, D2, 4V on a two or three dollar drill. I don't resharpen, I just replace it at the start of the next run. A tube of a dozen drills lasts a year.

I've had problems with a spit point occasionally getting a chip stuck on one side of the split and making the drill cut oversize.

I feed hard enough to break the chip so there are no birds nest. I sometimes drill a pilot hole on holes over 1/2" (depending on the machine), though that doesn't come up often.

Drilling is one of those things that knife makers make unnecessarily difficult on themselves. They tend to dull drills by under feeding which allows things to rub and wear. Then they over feed as the point exits the back of the work, wiping out the corners. Ideally you don't peck because we're cutting work hardening materials, but you may need to if you're cutting dry.