DIN 17175 ST35.8 Seamless Carbon Steel Pipes Hollow AISI 1020 Mild Steel
seamless pipes grades and production methods
1. 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, then make precision processing to make outer diameter and inner diameter as requested. Any size hollow bar can be produced as demanded.
Tolerance for hollow round bar, forged round bar drilling hole hollow bar ASME SA530
|Type||Outer diameter(inner diameter)||Allowed tolerance||Wall thickness allowed tolerance|
|≥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|
length tolerance -0 - +50mm
Round bar making Hollow bar cost is high
2. Hot rolled Hollow Bar
using hot rolled steel pipe billet to make heating and piercing, elongating, sizing and stranghtening, cooling, finally hollow bars finished, this is the type most commonly used. Because it is hot rolled, so cost is lowest, but it is suit for large quantity, for small quantity, have to make cold drawn or round bar piercing. size: outer diameter 32mm- 499mm, wall thickness 4mm- 80mm
3. Cold drawn Hollow Bar
for outer diameter not over than 63.5mm, small size hollow bar, when demanded quantity is under 5 tons, usually make cold drawn hollow bar, using larger size hot rolled hollow bar to draw to the size demanded.
some size can be finished only by one time drawing, but some other sizes might need twice or three times to finish drawing, it takes time, so the cost is higher.
cold drawn size outer diameter 32mm- 63.5mm
4. Hot- expanding Hollow Bar
For hollow bar sizes are special, not common sizes, have to use smaller thick wall hollow bar to hot expand to be larger size hollow bar, but the technical property for hot-expanded hollow bar will be lower than the original hollow bar. Size: outer diameter over 356mm.
the seamless pipe grades can be supplied
Seamless Steel pipe 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|
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