Conventional representation of standard features

Conventional representation of standard features

Conventional representation of standard features

Conventional representation of standard features

Conventional representation of screw threads

Conventional representation of screw threads

Fig. extracted from Engineering Drawing (Part 1) by M.A. Parker and F. pickup

Conventional representation of screw threads

Fig. extracted from Engineering Drawing (Part 1) by M.A. Parker and F. pickup

Conventional representation of screw threads

Fig. extracted from Engineering Drawing (Part 1) by M.A. Parker and F. pickup

Conventional representation of screw threads

Fig. extracted from Engineering Drawing (Part 1) by M.A. Parker and F. pickup

Conventional representation of screw threads

Fig. extracted from Engineering Drawing (Part 1) by M.A. Parker and F. pickup

Dimensioning of screw threads

Threads shown on engineering drawing must be designated completely by dimensions or a note.

ISO metric threads are designated in the following examples.

M18 x 2.5 – 6g external thread

M18 x 2.5 – 6H internal thread

M = Thread system symbol for ISO metric.

18 = Nominal diameter in mm.

2.5 = Pitch in mm.

6g = External thread tolerance class symbol.

6H = Internal thread tolerance class symbol

Dimensioning of screw threads

The external and internal thread tolerances provide

three classes of fit as the following:-

1. The close fit 5H/4h is used when close accuracy of thread form and pitch is needed.

2. The medium fit 6H/6g is suitable for most general engineering purposes.

3. The free fit 7H/8g is used for applications requiring quick and easy assembly.

Dimensioning of screw threads

Fig. extracted from Engineering Drawing (Part 1) by M.A. Parker and F. pickup

Dimensioning of screw threads

Fig. extracted from Engineering Drawing (Part 1) by M.A. Parker and F. pickup

Drawing hexagon nuts

Fig. extracted from Engineering Drawing (Part 1) by M.A. Parker and F. pickup

Drawing hexagon nuts

Fig. extracted from Engineering Drawing (Part 1) by M.A. Parker and F. pickup

Drawing hexagon nuts

Fig. extracted from Engineering Drawing (Part 1) by M.A. Parker and F. pickup

Screw Fasteners

Fig. extracted from Engineering Drawing (Part 1) by M.A. Parker and F. pickup

Screw Fasteners

Fig. extracted from Engineering Drawing (Part 1) by M.A. Parker and F. pickup

Screw Fasteners

Fig. extracted from Engineering Drawing (Part 1) by M.A. Parker and F. pickup

Screw Fasteners

Fig. extracted from Engineering Drawing (Part 1) by M.A. Parker and F. pickup

Screw Fasteners

Fig. extracted from Engineering Drawing (Part 1) by M.A. Parker and F. pickup

Screw Fasteners

Fig. extracted from Engineering Drawing (Part 1) by M.A. Parker and F. pickup

Screw Fasteners

Fig. extracted from Engineering Drawing (Part 1) by M.A. Parker and F. pickup

Locking Devices

Locking Devices

The End