DIN 1629 ST44.0 seamless circular tubes of non alloys steels with special quality requirements

Steel Grade

Type of deoxidization
(R, killed (including semi-killed)) (RR,fully killed)

Chemical Composition, % by mass

Symbol

Material Number

C

P

S

N¹)

Addition of nitrogen fixing elements
(e.g.not less than 0,020% Al total

St44.0

1.0255

R

0.21

0.040

0.040

0.009²)

-

Upper Yield Stress ReH
for wall thickness, in mm,

Tensile strength
Rm
N/mm²

Elongation(%) A5

Symbol

Material Number

up to 16

over 16 up to 40

over 40 up to 65

Longitudinal

Transverse

St 44.0

1.0256

275¹)

265¹)

255¹)

420²) to 550

21

19

¹) For cold f inished tube in the NBK condition (annealed above the upper transformation point under shielding gas or in a vacuum), minimum values of yield stress lower than these valued by 20N/mm² are permitted.
²) For cold finished tubes in the NBK condition, minimum values of tensile strength lower than these values by 10N/mm² are permitted.