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Table 4.17
Nominal Thread L, l , D 1, D 2, b, R 1, R 2, S,
bore, Dy, G, inch mm mm mm mm mm mm mm mm
mm
10 3/8 25 10.0 24 22 2.0 4 6.5 2.5
15 1/2 28 12.0 28.6 26.6 2.0 2.7 5.5 2.8
20 3/4 33 13.5 34.9 32.4 2.5 3.3 6.3 3.0
25 1 38 15.0 42.1 39.6 2.5 3.2 6.5 3.3
32 1 45 17.0 52 49 3.0 3.4 7 3.6
40 1 50 19.0 59 56 3.0 3 7 4.0
50 2 58 21.0 70.5 67 3.5 2.5 7 4.5

The example of the conventional denotation of a tee with the nominal bore 20 mm: Tee 20
State Standard 8948-75.

The drawing of a joint is begun with the drawing of a pipe, then the view of connecting parts
are drawn according to the sizes in tables (4.12 – 4.17). A pipe on the drawing is shown by not
screw up in a connecting part on 2-4 mm (1-2 threads), that is why a thread on a pipe is at the face
of the connecting part. Figure 4.32 shows the drawing of the pipe joint by a pipe coupling. An
external thread on a pipe is drawn the same as on the bar of a bolt by a continuous contour line on
the most diameter and by a continuous thin line on the internal diameter of a thread. Such view of a
thread on a pipe will be in joint with other parts.

Figure 4.32 – Pipe joint by a pipe coupling

An internal thread in connecting parts remains unchanging only in the places not taken by the
pipe.

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