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

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