Standdard according to ASTM B360

O.D.(Inch)		Thickness
Inch	mm	Inch	mm
3/16	4.76	0.008 ~ 0.012	0.20 ~ 0.30
1/4	6.35	0.008 ~ 0.014	0.20 ~ 0.35
5/16	7.94	0.008 ~ 0.014	0.20 ~ 0.35
3/8	9.52	0.008 ~ 0.014	0.20 ~ 0.35
1/2	12.7	0.008 ~ 0.014	0.20 ~ 0.35
5/8	15.88	0.010 ~ 0.016	0.20 ~ 0.41

  * to be adjusted as specific requirement.