Originally designed for metalworking, the transfer punch is just as useful in the woodworking shop.
Copying the hole pattern from a piece of equipment to it's mounting base by rotating a pencil in the hole seldom works very well. Most times at least one hole will be out to lunch, and you'll have to drill the hole several times oversize to get the bolt to line up.
With a set of metal punches called transfer punches, you can eliminate the Fred Flintstone method and mark the exact center of the holes every time. I use mine frequently for transfering hole patterns from templates, but they're useful for many other jobs as well.
28 piece set - 3/32 to 17/32 .
The most common punch set contains 28 punches ranging in size from 3/32 to 17/32 inches, which is ideal for the home workshop.
They're also available in letter drill, wire drill and metric sizes, but the average woodworker will seldom find a need for these.
Imported sets like the one in the photo on the right are priced in the twenty dollar range, but top of the line brand names can be eighty dollars or more. The imported sets are more than adequate for woodworking though and this inexpensive set from Amazon would do the job nicely.
A closer look at the punch tip.
The tip of the punch is tapered like a center punch, but is much shorter. This allows it to be used in shallow holes and still contact the sides of the hole for accuracy.
The tip ends on the punches are usually hardened and tempered for use on steel, so if you only use them on wood or plastic, they should last forever.
Transfering the mounting screw hole location from a table saw insert to an oak board.
In the photo on the right I'm using my stock table saw insert as a template to fabricate a zero clearance table saw insert out of oak.
After tracing the outline, I use a punch to mark the center for the mounting screw hole and the four leveling holes.
Choose the punch that has the best fit in the hole. A light tap with a small hammer is sufficient to leave a nice center punch in wood.
You'll find many uses for these punches, from mounting a vise to a workbench to building jigs and fixtures.
There's nothing worse than drilling a hole off center and having to elongate the hole with a rasp to get it to line up. Tacky. Get a set of these punches and drill your holes accurately.