JIS G 3473 Hydraulic Cylinder Tube ,  Round Carbon Steel Tube for Cylinder Barrels

CHEMICAL COMPOSITION %  max

Steel grade

C

Si

Mn

P

S

Nb or V

STC 370

0.25

0.35

0.30-0.90

0.04

0.04

-

STC 440

0.25

0.35

0.30-0.90

0.04

0.04

-

STC 510 A

0.25

0.35

0.30-0.90

0.04

0.04

-

STC 510 B

0.18

0.55

1.5

0.04

0.04

-

STC 540

0.25

0.55

1.6

0.04

0.04

0.15 max

STC 590 A

0.25

0.35

0.30-0.90

0.04

0.04

-

STC 590 B

0.25

0.35

1.5

0.04

0.04

-

Remark: STC 550 Nb in combination with V may be added. In this case the maximum value of Nb+V shall be 0.15%

MECHANICAL PROPERTIES min

Steel grade

Tensile strength Mpa

Yeild point or proof stress Mpa

Elongation %

STC 370

370

251

30

STC 440

440

305

10

STC 510 A

510

380

10

STC 510 B

510

380

15

STC 540

540

390

20

STC 590 A

590

490

10

STC 590 B

590

490

15

category

Tolerance on Wall thickness

Hot-finished seamless steel tube

±12.5% however the minimum  value is 0.5mm

Cold-finished seamless steel tube

±10% however the minimum  value is 0.3mm

Cole finished electric resistance welded steel tube

±8% however the minimum  value is 0.15mm

Processes of manufacture and heat treatment

Designation of grade

Process of manufacture

Heat treatment

Application

STC 370

Hot finishing seamless

As manufactured

Cutting

STC 440

Cold finishing electric resistance welding

As cold drawn or stress relieving

Honing

STC 510 A

Cold finishing seamless

As cold drawn or stress relieving

Cutting and honing

Cold finishing electric resistance welding

As cold drawn or stress relieving

Honing

STC 510 B

Cold finishing seamless

Stress relieving

Cutting and honing

Cold finishing electric resistance welding

Stress relieving

Honing

STC 540

Hot finishing seamless

As manufactured

Cutting

STC 590 A

Cold finishing seamless

As cold drawn or stress relieving

Cutting and honing

STC 590 B

Cold finishing seamless

Stress relieving

Cutting and honing