178, are a convenient device for drawing together two pieces of wood, when injury to the surfaces in which they are driven does not matter.

They vary in size from 3/4" to 2-3/4".

For ordinary purposes the smallest size is sufficient.

For especially fine work, double-pointed tacks, properly filed, are convenient.
The _bench-hook_, Fig.

179, is a simple device for holding firmly small pieces of work when they are being sawn, chisled, etc.