SCM440 SCM420 Steel Pipes

Product Detail

SCM440 SCM420 Steel Pipes material Equivalent Grades: 


GB 20CrMo, JIS SCM420, ASTM 4118, DIN 25CrMo4. SCM440 STEEL PIPES SCM440 STEEL PIPES SCM420 STEEL PIPES materials are alloy steel with high harden ability, temper brittleness, well weld ability, less cold cracking tendency, good machinability, and great cold plastic strain. SCM420 generally are used for the parts which need high wear resistance, such as gears, shafts, high-pressure pipes, all kinds of fasteners, and so on.




SCM420 is widely used in general structural steel.





Conditions of heat treatment

· Annealing: 850? Furnace Cooling

· Normalization: 850~900? Air Cooling

· Hardening: 850~900? 1st Oil Cooling, 800~850? 2rd Oil Cooling

· Tempering: 150~200? Air Cooling




Criterion for heat treating conditions revise:

· Ac: 770~835?

· Ar: 770~700?

· Ms: 410?




Mechanical properties

Tensile strength (kgf/mm2): ?95
Elongation (%): ?14
Cross section reduction rate (%): ?40
Impact value (J/cm2): ?6
Hardness (Hb) : 352~362

SCM440 STEEL PIPES SCM420 STEEL PIPES Size Range




Types of SCM440 SCM420 STEEL PIPES 

40Cr steel pipes

40Cr steel tubes

Economical SCM440 STEEL tubes

SCM435

42CrMo4

42CrMo | AISI4140 Alloy Steel Round Bar

JIS F 0014:2000 Glossary of terms for shipbuilding (hull part -piping)

JIS F 0301:1990 Schemes of thermal insulation of piping for small ships

JIS F 0414:1996 Shipbuilding - internal wiring and piping of engine control console

JIS F 0506:1996 Shipbuilding - applications of copper pipes

JIS F 0507:1992 Small ships - steel pipes - application

JIS F 2007:1976 Mooring pipes

JIS F 2030:1978 Single point mooring pipes

JIS F 3993:1996 Discharge pipes for dredger

JIS F 3994:1996 Floaters of discharge pipes for dredger

JIS F 3995:1991 Rubber sleeves for dredge discharge pipes

JIS G 3429:1988 Seamless steel tubes for high pressure gas cylinder

JIS G 3439 Seamless steel oil well casing, tubing and drill pipe

JIS G 3441:2004 Alloy steel tubes for machine purposes

JIS G 3442:2004 Galvanized steel pipes for ordinary piping

JIS G 3443:2004 Coated steel pipes for water service

JIS G 3444:2004 Carbon steel tubes for general structural purposes

JIS G 3445:1988 Carbon steel tubes for machine structural purposes

JIS G 3446:1994 Stainless steel pipes for machine and structural purposes

JIS G 3447:2004 Stainless steel sanitary pipes

JIS G 3448:2004 Light gauge stainless steel tubes for ordinary piping

JIS G 3451:1987 Fittings of coated steel pipes for water service

JIS G 3452:2004 Carbon steel pipes for ordinary piping

JIS F 7008:1996 Standard specification of thermal insulation for piping

JIS F 7101:1993 Pipes of ship's machinery - standard velocity of flow

JIS G3445 STKM11A STKM12A STKM12B STKM12C STKM13A STKM13B STKM13C STKMI4A STKM14B STKM14C STKM15A STKM18C STKM16A STKM18C STKM17A STKM17C STKM18A STKM18B STKM18C STKM19A STEEL TUBES STKM19C STKM20A STEEL TUBES