 | Manual Thread Cutting - Course: Technique for manual working of materials. Trainees' handbook of lessons (Institut für Berufliche Entwicklung, 22 p.) |
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6. Special hints on the designation of threads by the example of the metric threads
Fastening screw threads are internationally standardized in a different way. A large group of these kinds of threads is the group of the metric ISO threads marked by a uniform designation.
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Metric ISO threads |
Example of the designation of a coarse screw thread:
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M 8 |
M = metric thread
8 = nominal diameter 8 mm
Example of the designation of a fine screw thread:
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M 10 x 1.25 |
(The fine screw thread is additionally marked by the indication of the thread pitch)
M = metric thread
10 = nominal diameter 10 mm
1.25 = thread pitch 1.25 mm
The designation is to be found on the shank of the thread tap or on the surface of the threading die or the die-stock dies, respectively. In addition, symbols for left-hand threads may appear after the designation.
Note:
The designation of the threads is identical on cutting tools and testing tools - with a certain cutting tool the matching testing tool must be used.
What is the designation of a thread limit plug gauge by which a
bore shall be checked cut by a M 8 nut
tap?
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What is the meaning of the designation M 6 x
0.5?
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