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Mechaniker (Siemens & Halske)
screw thread series

In use as late as 1925. "Post-gewinde" = Postal screw, sizes in use by the Reichspost.

Number	Diameter in mm	Pitch in mm	Threads per inch	deg	Comment
1	15.84	0.8965	28 1/3	75
2	13.07	1.0160	25	52
3	12.30	1.4711	17 17/64	54
4	11.37	1.8246	13 23/25	59
5	11.02	1.0477	24 8/33	52
6	10.86	1.3170	19 2/7	57
7	10.16	0.9596	26 8/17	66
8	9.40	1.1545	22	52
9	9.24	1.2543	20¼	55
10	8.91	1.5804	16 1/14	58
11	8.965	1.2192	20 5/6	50	post-gewinde
12	8.75	1.4962	16.368/377	57
13	8.28	0.9721	26 4/31	52
14	7.20	1.0367	24½	58	post-gewinde
15	6.64	0.6047	42	58
16	6.28	1.1723	21 2/3	62
17	6.00	0.8965	28 1/3	55	post-gewinde
18	5.75	0.7815	32½	48	post-gewinde
19	5.58	1.0367	24½	62
20	5.30	0.5229	48 4/7	53
21	5.12	0.7815	32½	58	post-gewinde
22	4.67	0.5229	48 4/7	62
23	4.21	0.4127	61 7/13	60
24	4.21	0.7968	31 7/8	63
25	4.00	0.6684	38	61	post-gewinde
26	3.43	0.5941	42¾	55
27	3.37	0.6684	38	68	post-gewinde
28	2.89	0.6684	38	68
29	2.80	0.5347	47½	66	post-gewinde
30	2.61	0.5027	50 10/19	58
31	2.16	0.4980	51	68	post-gewinde
32	1.80	0.4141	61 1/3	75
33	1.78	0.3463	73 1/3	59	post-gewinde
34	1.63	0.3023	84	55	post-gewinde
35	1.38	0.2822	90	72
36	1.22	0.2260	112 9/26	50	post-gewinde

Thread data contributed by Job Visser, who suggested this entry.

Georg W. Berndt.
Die Gewinde; ihre Entwicklung, ihre Messung und ihre Toleranzen.
Berlin: J. Springer, 1925.
Page 115.

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