Blacksmith’s Riveting, Brazing and Welding, part 2

In our previous post we talked about how we use mechanical joints, brazing and electrical welding to fasten metal parts together for tools and jigs in the shop. In the work we do for Horton, we use only riveted fastening: we head pins for hinges much like we’d head a rivet, and in making Suffolk latches we rivet the thumber into its slot.

While riveting is perhaps the most common type of fastening in period hardware, other types of connection were also used. We’ll be looking at a lever latch with lock, much like the one mentioned in our post on books. It’s much like the one illustrated in the Sonn and Streeter examples in that post.

This is the back of a German-style lever latch that also included a simple lock. The back plate to this latch is held in place with four nuts.

Each nut has filed decoration, even though this part of the latch would not be seen. The nuts and threaded posts are each individually sized. No nut will fit all the posts.

On the other side of the back plate a spring that holds the bar in place has been riveted.

This is the latch and lock with the back plate removed. There are only a couple of moving parts: the lever and its spring, the tumbler which holds the bar in place (the tumbler spring has broken), and the bar (note the filed decoration at the end, again this was hidden from view). The broken spring for the tumbler would be easy to replace; it is held by a rivet. Studs for the latch spring and tumbler were riveted to the front of the case, as were the two guides for the bar.

The latch handle, as you can see in the above photo, consists of a forging with a handle at one end and, after a ninety-degree bend, a bar that rises in and out of a catch in the doorjamb. The handle’s pivot (where the pencil rests) is a round piece with a square hole (to hold the handle for the other side of the door). The pivot rides in holes cut into the front and back plates of the latch. This pivot is brazed to the handle, in this case using copper instead of brass.

Brazed joints are also found in tools. The vise shown in the post about artifacts has a bit of brazing. In this case, rather than try to tap a thread for the vise screw box (or nut), what they did was wrap a piece of square wire around the vise screw and insert it in the box or nut. The vise screw was carefully removed leaving the wire in place. Brass filings were sprinkled inside and the whole was heated in the fire to braze the wire to the box.