Chris Ticktock News Today

Hi Guys, This is a piece off a Gustav Becker wall clock. This piece is part of the escapement mechanism. However this clock has a friction washer that pushes the tri pointed brass onto a 9mm Dia piece of brass. The pressure of the spring is there to maintain position but allow adjustment if necessary. My question is as the pressure from the steel friction spring puts pressure on the 2 brass surfaces, the smaller being 9mm Dia is there a way to optimise friction between the 2 bra...

Its that apparent size reduction that seems to have thrown you. Thread crests are normally slightly below nominal size. It avoids sharp crests and clears the female thread root, which itself is radiused to minimise stress-raising. The actual reductions are as carefully standardised as the pitches, angles, etc.. An M4 screw I happened to measure only this afternoon, to verify it was indeed M4, was 3.7mm dia., too. It will be worth you obtaining sets of thread tables to go with the thread-gauges...