Name

EN10305 E235 precision seamless steel tube

Standard

Din 2391

Material

St35,St45,St52

Supply Condition

Cold drawn seamless steel tube, stress relieved and honed or skived roller burnished

Appearance

Tube shall have a smooth internal and external surface consistent with cold working process,

tube inner surface should be free from rust, scratches and other surface irregularities.

Appearance

Tube shall have a smooth internal and external surface consistent with cold working process,

tube inner surface should be free from rust, scratches and other surface irregularities.

Tolerance on Outer Dia.

≤ Dia 40 +/-0.2 mm
≥ Dia 40 ≤ Dia 100 +/-0.3mm
≥ Dia 100 +/-0.5mm

Surface Roughness

Ra = 0.4~0.8 Micron

Application

Cold drawn or cold rolled precision seamless steel tubes for hydraulic pressure and pneumatic s

ervices.For Auto use,machinery use,oil cylinder tube,motorcycle shock reducer use,auto shock

reducer inner cylinder,etc.Seamless steel pipes for low and medium pressure boiler, high pressure

boiler, ship-building,Liquid service, petroleum cracking, chemical fertilizer equipment,Drawing-oil-equipment and structure purposes.

material

Chemical Composition(%)

C max.

Si max.

Mn

P max.

S max.

St 35

0.17

0.35

³0.40

0.025

0.025

St 45

0.21

0.35

³0.40

0.025

0.025

St 52

0.22

0.55

£1.60

0.025

0.025

can add the following elements: Nb:£0.03%;Ti:£0.03%;V:£0.05%;Nb+Ti+V:£0.05%

The mechanical properties of the tube at room temperature

material

Cold finished (hard)BK(+C)

Cold finished (Soft)BKW
(+LC)

Cold finished and stress-relieved BKS(+SR)

Tensile Strength(σb/MPa)

Elongation(δ5/%)

Tensile Strength(σb/MPa)

Elongation(δ5/%)

Tensile Strength(σb/MPa)

Yield Point(Mpa)

Elongation(δ5/%)

St 35

480

6

420

10

420

315

14

St 45

580

5

520

8

520

375

12

St 52

640

4

580

7

580

420

10

The yield strength of annealed state should be at least equal to the tensile strength of the 50%.

According tothe differentdegree of deformation,Cold working (hard) and cold (soft) yield strength

state may be close to the tensile strength.When calculating, Cold working (hard) state should be

at least 50% of the tensile strength as the foundation, and the cold working(soft) state is 70%.

material

Annealed GBK(+A)

Normalized NBK(+N)

Tensile Strength(σb/MPa)

Elongation(δ5/%)

Tensile Strength(σb/MPa)

Yield Point(Mpa)

Elongation(δ5/%)

St 35

315

25

340-470

235

25

St 45

390

21

440-570

255

21

St 52

490

22

490-630

355

22

The yield strength of annealed state should be at least equal to the tensile strength of the 50%.

According to the different degree of deformation,Cold working (hard) and cold (soft) yield strength

state may be close to the tensile strength.When calculating, Cold working (hard) state should be

at least 50% of the tensile strength as the foundation, and the cold working(soft) state is 70%.