Cast Threaded Brass Tangents  Cast threaded brass tangents are
now offered in two lengths, 28mm and 32mm. These tangents are
slightly softer than the strings they will be hitting. They are
‘as cast’ and therefore as supplied are in their softest state.
The tops are polished smooth, and cut at a very slight angle
(highest away from the player, naturally); this should help keep
the string in place.  Tangents should be screwed in using a tool
of steel with a tapered slot sawn and filed into the end (an old
screwdriver is ideal). If the keys are made of a really hard bit
of lime it can help if a couple of longitudinal grooves are
filed at the start of the thread, like a tap. The only
lubrication permitted is tallow, since all other things, (for
instance soap) eventually behave like glue; but I don’t
recommend using anything. Most of your adjusting for height will
be done within a week or so of the instrument becoming stable.
Now I know these are not like ‘original’ tangents, but I have
never been comfortable with