It’s certainly not an essential tool but if you ever come by an expansive auger it’s definitely worth grabbing as they’re a great get out of shite card in the workshop. I’ve had this one for years and its come in useful many times when drilling out for something a bit obscure. It goes right up to 3″ diameter which is a pretty big hole, and when you need a big hole you really do need one.
Fitting vices especially ones with large wooden screws tends to call for big drill bit sizes which you’ll rarely need for any other task, and when I look at the price of some of the larger bits it’s easy to see it can get expensive fast, which is especially annoying if you’re only likely to use the bit once.
An expansive auger can be a fiddly thing to set up but being able to do right from the smaller 3/4″ (on this example) right up to 3″ you do have the ability to infinitely tune to any size you wish and there are times when you might want to choose a particular tolerance for a hole rather than being stuck to the common fixed diameters. The grace with fitting vices is that the large holes are usually just for clearance and so there’s no need to be too accurate with the precise diameter here.
Sharpening is easy enough and whilst an auger file is ideal for this a small saw file can also do the job if you’re struggling to find one.
I won’t pretend that drilling a hole in the 3″ diameter region is easy, or not by hand at least anyway. It’s bloody hard work pushing the brace round but these bits do cut fast and clear the waste out well. They have a tendency to break through if you let them and make a mess of your underside, so I like to stop just as the centre screw pokes through the bottom and then flip my work over and come back in from the other side.