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Cold drawing: the tube is pulled through a die over an inner plug (mandrel), which sizes both the outside and the inside diameter and thins the wall.
Cold drawn seamless precision steel tubes from China: standards, grades, delivery conditions and the specs to send for a quote.
Cold drawn precision tubes are seamless tubes drawn cold through a die over a mandrel, to reach close outside and inside diameter tolerances and a smooth surface. They are used for hydraulic and pneumatic lines, automotive parts, machine building, and as the starting tube for hydraulic cylinders.
Standards and grades you will see
| Standard | Typical grades |
|---|---|
| EN 10305-1 (Europe; replaced DIN 2391) | E215, E235, E355 |
| ASTM A519 (USA) | 1020, 1026, 4130, 4140 |
| GB/T 3639 (China) | 10, 20, 45, Q355 and others |
The delivery condition matters as much as the grade
Under EN 10305-1 the same grade can be delivered in different conditions, and they behave very differently in machining and bending:
| Condition | Old DIN name | What it means |
|---|---|---|
| +C | BK | Cold finished hard, no heat treatment after the last draw |
| +LC | BKW | Cold finished soft, light final pass |
| +SR | BKS | Cold finished and stress relieved |
| +A | GBK | Annealed |
| +N | NBK | Normalized |
Specs to send for a quote
- Standard, grade and delivery condition.
- Outside diameter and wall thickness (or outside and inside diameter), with the tolerances you need.
- Length: random or fixed, and the length tolerance.
- Surface protection: oiled, phosphated or other.
- Tests and certificate, for example EN 10204 3.1, eddy current testing and any mechanical tests.
- Quantity, packing and destination port.
How to order through SinoAli
Send us the specification above. Ask us which mill the material comes from and which certificate it carries. When your contract is with SinoAli, you pay the deposit only to the company account named in your contract, you choose the inspection company, and you pay the balance after you have seen the inspection report. Buying from a new supplier for the first time? Read How to buy steel from China without getting scammed.
