Page 320 - Mechanical Engineer's Data Handbook

308 MECHANICAL ENGINEER’S DATA HANDBOOK

0.3.3 Copper pipe sizes for domestic
water pipes, etc.

Size are given in BS 2871: Part 1.

Nominal thickness (mm)
Table X:
Size of Half-hard, Table Y: Table Z:
pipe* light half-hard, hard drawn,
(mm) gauge annealed thin wall

6 0.6 0.8 0.5
8 0.6 0.8 0.5
10 0.6 0.8 0.5
12 0.6 0.8 0.5
15 0.7 1 .o 0.5
18 0.8 1 .o 0.6
22 0.9 1.2 0.6
28 0.9 1.2 0.6
35 1.2 1.5 7.0
42 1.2 1.5 8.0
54 1.2 2.0 9.0
76.1 1.5 2.0 1.2
108 1.5 2.5 1.2

*Outer diameter.

8.4 Miscellaneous data

0.4. I Factors of safety
Tensile strength or Proof stress
Factor of safety FS= (sometimes based on yield stress)
Permissible working stress

Typical factors of safety for various materials
Type of load

Varying, of
Material Steady same kind Alternating Shock

Grey cast iron 4 6 10 15
Malleable cast iron 4 6 8 12
Carbon steel 4 6 8 12
Brittle alloys 5 6 10 15
Soft alloys 5 6 8 12
Timber 6 10 14 20
Brick 15 20 25 30
Stone 15 20 25 30