BS EN 1401- (BS 4660 & BS 5841) uPVC for underground drainage and sewerage
Nominal OD	Nominal O.D	Mean O.D(mm)		Wall thickness
(inch)	(mm)	min.	max.	min.	max.
3"	82	82	82.3	3.0	3.5
4"	110	110	110.3	3.2	3.8
6"	160	160	160.4	4	4.6
8"	200	200	200.5	4.9	5.6
10"	250	250	250.5	6.1	7.1