British Standard (BS 3505:1968)

Normal Size Outside Diameter Class B – 06
Bar		 Class C – 09
Bar		 Class D – 12
Bar		 Class E – 15
Bar
Wall Thickness Wall Thickness Wall Thickness Wall Thickness
Inch Min Max Min Max Min Max Min Max Min Max
0.50 21.20 21.50 1.70 2.10
0.75 26.60 26.90 1.90 2.50
1.00 33.70 33.70 2.20 2.70
1.25 42.10 42.40 2.20 2.70 2.70 3.20
1.50 48.10 48.40 2.50 3.00 3.10 4.50
2.00 60.20 60.50 2.50 3.00 3.10 3.70 3.90 4.50
3.00 88.70 89.10 2.90 3.40 3.50 4.10 4.60 5.30 5.70 6.60
4.00 114.10 114.50 3.40 4.00 4.50 5.20 6.00 6.90 7.30 8.40
5.00 140.00 140.40 3.80 4.40 5.50 6.40 7.30 8.40 9.00 10.40
6.00 168.00 168.50 4.50 5.20 6.60 7.60 8.80 10.20 10.80 12.50
8.00 218.80 219.40 5.30 6.10 7.80 9.00 10.20 11.90 12.60 14.50
9.00 244.10 244.80 5.90 6.80 8.70 11.00 11.50 13.30 14.10 15.80
10.00 272.60 273.40 6.60 7.60 9.70 11.20 12.80 14.80 15.70 18.10
12.00 323.40 324.40 7.80 9.00 11.50 13.30 15.20 17.50 18.70 21.60
14.00 355.00 356.00 8.50 9.80 12.60 14.50 16.70 19.20 20.50 23.60
16.00 405.00 406.90 9.70 11.20 14.50 16.70 19.00 21.90 23.40 27.00
18.00 456.70 457.70 11.00 12.70 16.30 18.80 21.40 24.60
20.00 507.50 508.50 12.20 14.10 18.10 20.90

British Standard (BS 3506:1969)

Normal Size Outside Diameter Class O
(Non-Pre)		 Class 6 Class 7
Wall Thickness Wall Thickness Wall Thickness
Inch Min Max Min Max Min Max Min Max
0.50 21.20 21.50 2.80 3.10 3.70 4.30
0.75 26.60 26.90 2.90 3.20 3.90 4.50
1.00 33.40 33.70 3.40 3.80 4.50 5.20
1.25 42.10 42.40 3.60 4.00 4.80 5.50
1.50 48.10 48.40 1.80 2.10 3.70 4.10 5.10 5.90
2.00 60.20 60.50 1.80 2.10 5.50 6.30
3.00 88.70 89.10 1.80 2.10
4.00 114.10 114.50 2.30 2.60
5.00 140.00 140.40 2.60 2.90
6.00 168.00 168.50 3.10 3.40
8.00 218.80 219.40 3.10 3.40
9.00 244.10 244.80 3.10 3.40
10.00 272.60 273.40 3.10 3.40
12.00 323.40 324.30 3.10 3.40
14.00 355.00 356.00 3.60 3.90
16.00 405.90 406.90 4.10 4.50
18.00 456.70 457.70 4.60 5.10