seamless pipes grades and production methods1. Round bar making Hollow Bar according to customer's demanded material to produce the round bar, then making annealled heat treatment, then drill the hole as customer demanded inner diameter into the round bar, round bar piercing, making rough hole......
| Type | Outer diameter(inner diameter) | Allowed tolerance | Wall thickness allowed tolerance |
Outer diameter | ≥219-457.2mm | -0.8 - +2.4mm | -0.8 - +4.0mm |
| >457.2-660.4mm | -0.8 - +3.2mm | ||
| >660.4-863.6mm | -0.8 - +4.0mm | ||
| >863.6mm | -0.8 - +4.8mm | ||
| Inner diameter | All size | -1.6- 0mm | 0 - +3.2mm |
| Descriptions | Grades |
| Structural pipe | 20# 35# 45# Q345B, 16Mn, Q345B-E, 20Mn2, 25Mn, 30Mn2, 40Mn2, 45Mn2 SAE1018, SAE1020, SAE1518, SAE1045. |
| Liquid pipe | 20# q295b-e, q345b-e |
| High pressure boiler tube | 20G 15MnG 20MnG 15CrMoG, 12Cr1MoVG St35.8, sa106b, sa106c, sa210a, sa210c, A333P2, A333P11, A33P12, A333P22, A33P36, A333P91, A333P92, A335T2, A335T11, A335T12, A335T22, A335T91, A335T23, A335T9 |
| Pipeline | API SPEC 5L, X42, X52, X60, X65,X70,X80 ASTMA53, ASTM A106, ASTM A333, BS301, BS3602, BS3603, BS3604, PSL1, PSL2, DNV-OS-F101, CSA-Z245 |
| Alloy pipe | 4140, 42CrMo, 32CrMo, 15CrMo, |
| Packing | Black paint, Varnish painting, Tarpaulin packing |
| End | Common round end, beveled. |
| Processing | Galvanizing; cutting; making thread outside the pipe; Machining. |
| outer diameter | 16mm- 800mm |
| wall thickness | 4mm- 80mm |









ASTM A519 1010 1020 1025 1045 Seamless Steel Pipe/Tube
1018 1019 1020 1021 1022 1023 1024 1025 Steel Pipe Mechanical Carbon Steel Pipe
ASTM A53 API 5L Round Black Pipe Carbon Seamless Steel Pipe
Seamless Carbon and Alloy Steel Mechanical Tube ASTM A519 1010/Mt1010
1018 1019 1020 1021 1022 1023 1024 1025 Steel Tube Mechanical Carbon Steel Tube
ASTM 1020 1025 Mild Carbon Steel Black Square Tube Pipe