GB/T 3639 Cold-drawn or Cold-rolled Precision Seamless Steel Tubes for Hydraulic Equipment
Products Description:
The GB/T 3639 is modified in relation to EN 10305-1: 2002( Steel tubes for precision applications-Technical delivery
conditions part 1: Seamless cold drawn tubes).The Cold-drawn or Cold-rolled Precision Seamless Steel Tubes are
produced in strict accordance with the Chinese GB/T 3639 standard. Carbon steel pipe billets are used as raw
materials, treated with imported lubricants from Europe, and manufactured by precision cold drawing or rolling.
These precision seamless steel tubes with special dimensional accuracy and high surface quality requirements
are suitable for mechanical structures, hydraulic equipment and automobiles.
Size Range:OD: 4-200mm, WT: 0.5-22mm, Length: acc to customer's requirement
Our Regular Size:31.75x2.55mm, 48.3x2.65mm, 50.8x2.4mm etc
Main Materials: ST35(E235),ST37,ST45(E255), ST52(E355), 10#, 20#, 35#, 45#, etc.
TORICH QUALITY ASSURANCE: High-precision, Good Surface Quality, Stable quality, Smooth Roughness
Production Processs: Seamless Cold Drawn or Seamless Cold Rolled + Heat Treatment
Main Delivery Conditions:NBK(+N) GBK(+A) BK(+C) BKW(+LC) BKS(+SR)
| Designation | Symbol | Description |
| Cold drawn/hard | +C | No heat treatment after the final cold drawing process. |
| Cold drawn/soft | +LC | After the final heat treatment there is a suitable drawing pass. |
| Cold drawn and stress relieved | +SR | After the final cold drawing process there is a stress relief heat treatment in a controlled atmosphere. |
| Annealed | +A | After the final cold drawing process the tubes are annealed in a controlled atmosphere. |
| Normalized | +N | After the final cold drawing operation, the tubes are normalized in a controlled atmosphere. |
Delivery Condition Symbol in Accordance With GB/T 3639 and EN10305-1.
| The standard classification and code name | The EN 10305-1:2002classification and code name |
| +C | BK |
| +LC | BKW |
| +SR | BKS |
| +A | GBK |
| +N | NBK |
The Standard Brand With the Original Standard Control
| The standard brand | The EN 10305-1:2002 brand |
| 10 | E215 |
| 20 | E255 (EN 10305-1 annex A) |
| 35 | C35E(EN 10305-1 annex A) |
| 45 | C35E(EN 10305-1 annex A) |
| Q345B | E355 |
Product Pictures of Precision Seamless Steel Tubes :
FAQ
Q: Are you trading company or manufacturer ?
A: A professional steel pipes materials inventor, manufacturer and solution provider.
Q: How long is your delivery time?
A:Generally it is 7-14 days if the goods are in stock. or it is 30-60 days if the goods are not in stock, it is according to quantity.
Q: Do you provide samples ? is it free or extra ?
A: Yes, we could offer the sample for free charge but need pay the cost of freight.
Q: What is your terms of payment ?
A: Payment<=1000USD, 100% in advance. Payment>=1000USD, 30% T/T in advance ,balance before shippment.
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