‌DIN 2391 Precision Seamless Steel Tube

St35, ST45, ST52, NBK / GBK / CW / SR

1. ‌Basic Specifications‌

• ‌Standard‌: DIN 2391 (German Industrial Standard for cold-drawn precision seamless steel tubes)‌1.
• ‌Material‌: Carbon steel (e.g., ST52 grade)‌8, suitable for mechanical and hydraulic applications‌6.
• ‌Surface Treatment‌: Options include phosphating (anti-corrosion treatment)‌4 and honed/bright surfaces (improved smoothness)‌

2. ‌Manufacturing Process‌

• ‌Cold Drawing‌: Precision cold-drawn process ensures dimensional accuracy and mechanical strength‌
• ‌Honing‌: Post-processing to achieve ultra-smooth internal surfaces for hydraulic systems‌

3. ‌Dimensions & Tolerances‌

• ‌Outer Diameter (OD)‌: 6-168mm
• ‌Wall Thickness‌: Tolerance within ±8% of specified thickness
• ‌Length‌: 5.8M / 6M / 11.8M , random length 5-5.8M

4. ‌Mechanical Properties‌

• High-pressure resistance and excellent load-bearing capacity‌
• Optimized for applications requiring tight tolerances and structural integrity‌

5. ‌Key Features‌

• ‌High Precision‌: Tight dimensional tolerances for seamless integration in complex assemblies‌
• ‌Surface Quality‌: Bright or honed surfaces reduce friction and enhance cleanliness in hydraulic/pneumatic systems‌
• ‌Durability‌: Enhanced strength from cold-working processes‌

6. ‌Applications‌

• ‌Hydraulic/Pneumatic Systems‌: Cylinder tubing and pipelines‌
• ‌Automotive‌: Precision components requiring high dimensional stability‌
• ‌Heavy Machinery‌: Structural parts in mechanical engineering‌

• Mechanical properties at room temperature

  Steel Grade

  Minimum values for the delivery condition

  Steel Name

  Steel Number

  BK

  BKW

  BKS

  GBK

  NBK

  Rm

  A %

  Rm

  A %

  Rm

  ReH

  A %

  Rm

  A %

  Rm

  ReH

  A %

  Mpa

  Mpa

  Mpa

  Mpa

  Mpa

  Mpa

  Mpa

  St 35

  1.0308

  480

  6

  420

  10

  420

  315

  14

  315

  25

  340 to 470

  235

  25

• Standard	Grade		Chemical Components (%)
  	Symbol	Material No.	C	Si	Mn	P	S
  DIN2391	St 35	1.0308	≤0.17	≤0.35	≥0.40	≤0.025	≤0.025

Keywords: DIN2391, Precision seamless steel tube, steel tube, seamless steel tube

Zhejiang New Era Steel Tube Technology Co., Ltd is one of the best seamless steel tube products manufacturer and exporter in china. Our main products include cold drawn and cold rolled seamless steel tubes .We can manufacture non-standard and special application tubes, also according to the international standards as well. Ningbo Pipeway Trade Co.,Ltd is our branch company for all internation business service for our company.

Our Production equipments including 16 cold drawing lines and 22 cold rolled machines:

We have full testing equipments for different kinds of testing for steel tubes:

Our products can produced as DIN,ASTM,ASME,EN,JIS,BS,GB,GOST,ISO etc international standard 

Precision steel tubes:DIN2391 st52/A519 4130 4140 1026/EN10305-1 E355+N/EN10305-4 E235+N

Boiler steel tubes:ASTM A192/A179/A210 Gr.A/A213;DIN17175 st35.8/EN10216

Seamless Mechanical tubes: ASTM A519, EN10297-1/EN10210 S355J2H

Wire line Drill Rods:BQ,NQ,HQ,PQ XJY750,XJY850 4130+SR 1541

Oil and Gas line pipes:API 5L Grade B,A106 Gr.B,A53 Gr.B,API 5D

Stainless Steel tubes 304,304L,316,316L

Steel pipes and tube Size range:OD 4-300mm,Wt:0.5-30mm

We have 15 years experience of exporting steel tubes and steel pipes , main exporting to American, Europe, Asian, Australia, Africa .

We have cerficate of ISO9001,TS16949,TUV/PED for different market demand: