Here is something you don't see any day: Forging die for Mauser M1914/34 frame

[ithacaartist]

Gerben,

This die is like a monster version of the dies for the Molloch 50 lb. "automatic hammer" at Durand's Forge, adjoining my workplace. Note that the upright part of the "T" shape visible in the side view has tapered sides. It is effectively a giant dovetail on each die, top and bottom. These slide into dovetail slots on the base of the machine and the moving "hammer", and are secured by pounding in a pair of long, matching-taper wedges. Presuming the sides of the dovetails and their slots are parallel, the wedges' tapers cancel each other to maintain parallel between the parts, and tighten the dies into the setup very effectively when driven in by striking their ends. The holes in the piece are probably for indexing the die on the machine, after which it would be secured by the wedges.

The advantage to hot forging--other than creating a shape that takes lots less machining to work into final shape--is that the grain of the steel remains uninterrupted and un-torn, which happens if the work-piece is bent cold, or cut by milling or cutting. The term "drop forge" has been mentioned. One of these works like an immense, heavy-duty guillotine. The top die rides to the top of the structure and is released either manually or automatically to fall upon the piece of red hot steel in the bottom die. Our hammer here is powered by a flywheel, with the energy controlled by a clutch between it and the hammer mechanism. With the clutch engaged, a heavy shaft rotates. The opposite end of the driven shaft contains the main flywheel, which has an off-center of attachment to the hammer, which when reciprocates vertically while the clutch is engaged. Ours turns a little fast, and is able to strike in excess of ten blows/second. Slipping the conical, leather-lined clutch allows for slower, more controllable action.