Latard

screw thread series

In the 19th – 20th centuries, a thread series used in Switzerland for manufacturing watches and clocks. It was realized in screw plates made by Martin, Perrelet et Martin, or Martin Fils. Plates marked “L” are the Latard series. (A “G” indicates left-hand threads.)

The series had 21 sizes, from 0 to 20. The thread form was V; we do not know the angle.

Compare Bourgeaux.

Size Diameter
in mm
Pitch
in mm
20 0.367 0.087
19 0.395 0.094
18 0.432 0.102
17 0.479 0.109
16 0.529 0.115
15 0.591 0.126
14 0.665 0.138
13 0.736 0.149
12 0.798 0.164
11 0.870 0.180
10 0.956 0.196
9 1.036 0.209
8 1.106 0.219
7 1.181 0.233
6 1.269 0.246
5 1.363 0.262
4 1.464 0.284
3 1.568 0.304
2 1.703 0.325
1 1.869 0.342
0 2.029 0.352

Diameter and pitch data contributed by Job Visser.

Georg W. Berndt.
Die Gewinde; ihre Entwicklung, ihre Messung und ihre Toleranzen.
Berlin: J. Springer, 1925.
Page 66.

home | tools index | search |  contact drawing of envelope |  contributors | 
help | privacy | terms of use