Seamless steel pipe
Normal Seamless Pipe
JISG 3454 ,ASTM A53/A106   10-219mmx1-40mm

BIGGER SEAMLESS PIPE
1.For structural Purposes 
Standar:DIN1629,ST37/44/52 ,EN10210-1 S355,GB/T8162
DN standard&sizes
Size:133mmx4.5mm---323.9mmx22.2mm
GB stadard&sizes
133mmx4.5mm--335mmx22mm

2.Boiler pipe
GB3078/5310,ASME SA`06B/C
114,3MM--325MM

3.Line Pipe
GB/T19711.1/2/3  ,API 5L PSL1/2,A/B/X42/X52
168.3mmx6.4mm---323.9mmx20.6mm

For the above some small sizes thickness can reach to 28mm
For more details,pls ctc directly!(mail ID:steelgoods@yahoo.cn.)Tks