Manual Thread Cutting - Course: Technique for manual working of materials. Trainees' handbook of lessons (Institut für Berufliche Entwicklung, 22 p.): 6. Special hints on the designation of threads by the example of the metric threads

Manual Thread Cutting - Course: Technique for manual working of materials. Trainees' handbook of lessons (Institut für Berufliche Entwicklung, 22 p.)

(introduction...)

1. Purpose of thread cutting

2. Kinds of threads

3. Tools for internal threading (tapping)

4. Tools for external threading

5. Operation of thread cutting

6. Special hints on the designation of threads by the example of the metric threads

7. Technological process of cutting internal threads (tapping)

8. Technological process of cutting external threads

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.

Metric ISO threads

Example of the designation of a coarse screw thread:

M 8

M = metric thread
8 = nominal diameter 8 mm

Example of the designation of a fine screw thread:

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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