Best Drill Bits?

[Derek Cohen]

Jig for training the hand to sharpen twist drill bits

There are two important criteria to watch out for when sharpening twist bits:

1. Maintain a constant, symmetrical angle that meets in the centre, such that the cutting angles are identical .... 118 degrees is the typical included angle for wood, and this is 59 degrees each side (135 degrees for steel). Meeting in the centre adds balance to the cutting action. Too sharp an angle will not cut as the sides may just rub against the material.

2. The bevel requires a relief angle, that is, there is a higher bevel angle behind the cutting edge (the heel of the bevel). Without this, the cutting edge cannot penetrate the material (as above, will just rub against the wood). To do this you will progressively raise the bit on the grinder wheel ... cutting a slight arc (instead of a single flat).

While all this sounds complicated when laid out like this, in practice it is a simple sweeping motion of the bit on the face of a grinder wheel along with a rotation of the bit on the face.

Here is a short video by Mathias Wandel, who uses the same method as I ...

https://www.youtube.com/watch?v=KkDe...MatthiasWandel


To aid those starting out to maintain the angle and facilitation the sweep, I came up with this little jig ...



The fence is set at 59 degrees. There is no specific diameter required for the dowel - just large enough to make rotation easy.



The method is simply to push the bit into the wheel, create the flat to the centre of the cutter, and then slide the bit up the wheel (lowering the end of the bit) while using the dowel as a pivot and the fence as a guide ...



After some practice runs, you should be ready to do this freehand using a finger as a rest.

Should take under a minute in all.

Regards from Perth

Derek

[Ray Selinger]

On a metal working forum this question came up. One reply mentioned no matter the brand they were all likely made in the same factory in Brazil. Drill bits are small potatoes, not worth the bother. We would go through a fair number of drills at work. The purchasing agent thought he would get smart and buy imported ones. I would simply grab a handful. It would take that many. Small bits are tossed, large ones I freehand sharpened. We went back to the Cleveland brand. A good cobalt drill like the Butterfields, will last about 20x longer then say even the Cleveland ones. They were that much better !

For wood, a good brad point like the Fullers will out last you, even if you are in your 20s. But different types have their own uses, even old fashioned spade bits, if you can spin them fast enough.

[Patty Hann]

On a metal working forum this question came up. One reply mentioned no matter the brand they were all likely made in the same factory in Brazil. Drill bits are small potatoes, not worth the bother. We would go through a fair number of drills at work. The purchasing agent thought he would get smart and buy imported ones. I would simply grab a handful. It would take that many. Small bits are tossed, large ones I freehand sharpened. We went back to the Cleveland brand. A good cobalt drill like the Butterfields, will last about 20x longer then say even the Cleveland ones. They were that much better !

For wood, a good brad point like the Fullers will out last you, even if you are in your 20s. But different types have their own uses, even old fashioned spade bits, if you can spin them fast enough.

Some of the OSG brand are still made in Japan. Maybe it's "lower" line is made in Brazil.
Definitely a price difference between the two lines.

[Michael Burnside]

The best I've used are fuller and viking. What's the best I haven't used? How would I know?

I have a set of Fisch double-flute bradpoint for woodworking. I’m with you, like them a lot. Best? I don’t know but they make a nice clean hole and are straight.

[Carroll Courtney]

First, thanks Derek for info and pics.
Thanks for all responses, lot of good info here for all who are tired of cheap drill bits. I have couple sets of drill bits that I had purchase years ago in metal containers. I think they came from Sears maybe in 70’s. Over time the smaller ones break and bigger ones just become dull. I want to replace one’s missing with good ones. Looks like have few choices, so going to go with ones made here in US. SMC has come through, thanks

[mike stenson]

First, thanks Derek for info and pics.
Thanks for all responses, lot of good info here for all who are tired of cheap drill bits. I have couple sets of drill bits that I had purchase years ago in metal containers. I think they came from Sears maybe in 70’s. Over time the smaller ones break and bigger ones just become dull. I want to replace one’s missing with good ones. Looks like have few choices, so going to go with ones made here in US. SMC has come through, thanks

Those are probably worth sharpening