brad point vs twist point

[Paul Fisher]

what is the different application? woodcrafters is having a sale and I am interested just not sure which to get or get both sets. thanks

[Ed Pawlowski]

Brad point drill bits leave a flat bottomed hole and clean edge at the entry point. They are particularly good if you want to plug the holes to cover screw heads or a recess fro Euro hinges. Good do hot out a mortise also. I use them much more for wood than twist drill. They are useless on metal though.

[Rick Samuel]

Correct, not for metal. It's a good buy, picked up a box last year, on sale. They won't walk off like a twist point can, like when using a hand drill....

[LEGEND65]

Brad point makes a cleaner entry and exit and doesn't slide off the mark.

Regular will self-center if you need to enlarge a hole and is easier to resharpen.

-Kevin

[whit3rd]

On Feb 4, 3:38=A0am, "Rick Samuel" wrote: [about brad point drill bits]

While they may not be intended for metal, brad point bits are nicely suited to soft (aluminum or copper) metal sheet drilling; the holes are much neater than with standard drills. On full thickness metals, or brass, they don't work as well.

[John Martin]

There are brad point bits, and there are brad point bits.

Sheet metal workers often ground their own brad point bits. Typical general purpose metal bits are ground at 59 degrees, so that the angle between the cutting edges is 118 degrees. The sheet metal bits were ground with an angle between the cutting edges of maybe 140 degrees, but in the other direction, and with a brad point in the center. The point centered the bit and the edges scored the circle. They work a lot better than regular metal cutting bits, which don't cut round holes in thin materials. Some of the woodworking brad point bits sold today are of this type.

The other type of brad point bits are for woodworking only. The cutting edges are ground at around 180 degrees, but spurs are left at the outer edges. The spurs cut cleaner in wood than the sheet metal bits do. They are more delicate, though, and I wouldn't use them in metal.

John Martin