| http://www.w3.org/ns/prov#value | - Also centerpunching is best avoided. (Spot drill, as Randy suggests) If you do ever need to centerpunch materials prone to workhardening, it is a good idea to grind four facets (like a pyramid) on the tip of the punch, so the action is a combination of cleaving and displacement, and the first contact of the drill is with the least displaced (hence softest) material.
|
