In Japanese standard JIS G4051, S45C and S50C are typical steel grades of medium carbon steel.Corresponding to the C45 and C50 steels in the European standard, and the AISI 1045 and AISI 1050 steels in the American grades,it should be said that they all play an important role in their respective regions.

As fully killed steels made by electric furnace, open hearth furnace or pure oxygen converter steelmaking,S45C and S50C steels have good machinability and are widely used in machinery manufacturing.As carbon steels with a carbon content of more than 0.4%, they have good wear resistance and average ductility.S45C and S50C steels have poor hardenability and are prone to cracking and deformation, so workpieces with large cross-sectional dimensions and high requirements should not be used.

S50C Forged round steel with Normalizing condition

WHAT DOES S45C/S50C MEAN?

If you want to know the meaning of the letters and numbers of S45C and S50C, you have to understand their naming rules. In fact, the naming principles of Japanese carbon steel grades are relatively simple. According to JIS(Janpanese Industrial Standard),the main part is as follows:

S X X C

S –Steel

XX–Average carbon content，Wc%x100

C–High quality carbon steel（sometimes with CK–Carburized steel)

From the above rules, we know that S45C means high-quality carbon steel with an average content of 0.45%, while S50C means that its carbon content is 0.50%

S45C | S50C STEEL CHEMICAL COMPOSITION

GradeCSiMnPS
S45C0.42-0.480.15-0.350.6-0.9≤ 0.03≤ 0.035
S50C0.47-0.53 0.15-0.35 0.6-0.9≤ 0.03≤ 0.035

S45C | S50C STEEL RELATED STANDARD & EQUIVALENT GRADE

S45CS50C
CHINA45#50#
USA10451050
EuropeC45C50
UKEN8/080M40EN9/070M55

S45C | S50C STEEL PHYSICAL PROPERTY

S45CS50C
Density, g/cm3 7.867.86
Ac1724℃725℃
Ac3780℃760℃
Elastic Modulus,Mpa209000207407
Shear modulus,Mpa8230081100
Poisson's ratio0.2690.29
Linear expansion coefficient,10^-6/k11.712.06

S45C | S50C STEEL FORGING

S45CS50C
Initial Forging Temperature1180℃-1210℃1100℃
Final Forging Temperature800℃800℃
Forging Ratio≥4:1≥4:1
Post-Forging TreatmentSlow coolingSlow cooling

S45C | S50C STEEL HEAT TREATMENT

S45C | S50C Steel Normalizing & Annealing

S45CS50C
Normalizing Temperature830~880℃820~870℃
Cooling MethodAir CoolingAir Cooling
AnnealingTemperature820-840℃820-840℃
Cooling MethodFurnance CoolingFurnance Cooling
Hardness<197HB<207HB
S45C | S50C Steel Mechanical Properties in Normalized & Annealed condition

GradeTensile Strength Yield StrengthElongationReduction of Area Impact Charpy-V Hardness
S45C Normalizing670-720Mpa340Mpa15-18%45-50%50170-240HBW
S50C Normalizing750Mpa425Mpa20%39%27217HBW
S45C
Annealing		532Mpa280Mpa32%49%60160-200HBW
S50C
Annealing		635Mpa365Mpa23.7%40%17187HBW

S45C | S50C Steel Quenching & Tempering

S45CS50C
QuenchingTemperature820~840℃810~830℃
Quenching mediumWaterWater
Quenching Hardness,HRC55-6058-63
TemperingTemperature500-540℃500-560℃
Cooling MethodAir CoolingAir Cooling
Hardness,HRC28-3230-35

S45C | S50C Quenching Limit Diameter

Quenching Medium
Still Oil20℃ Water40℃ Water20℃ 5%Nacl
S45C10mm20mm16mm21.5mm
S50C10mm20mm16mm21.5mm

S45C | S50C Steel Tempering Temperature Vs Hardness

GradeQuenchingTempering Temperature,ºC
Temperature,ºC Hardness,HRC150ºC 200ºC 300ºC 400ºC 500ºC 550ºC 600ºC
S45C840ºC 58-5958555041332622
S50C830ºC 58-5958555041332622

S45C Mechanical Property with Quenched and Tempered Condition

Quenching TemperatureQuenching MediumTempering TemperatureTensile Strength
Mpa		Yield Strength
Mpa		Elongation
%		Reduction of Area
%		Impact Charpy-V
J 		Hardness
820-840℃Water180-200℃≥1300≥1150≥6≥2215-2550HRC
820-840℃Water560-620℃700-850450-56015-1745-5060-80196-241HBW

S45C | S50C STEEL SUPPLY FORM & SIZE & TOLERANCE

Supply FormSize(mm)ProcessTolerance



Round		Φ6-Φ100Cold DrawnBright/Black Best H11

Φ16-Φ350
Hot Rolled		Black-0/+1mm
Peeled/ground Best H11

Φ90-Φ1000
Hot Forged		Black-0/+5mm
Rough Turned-0/+3mm

Flat/Square/Block		Thickness :120-800
Hot Forged		Black-0/+8mm
Width:120-1500
Rough Machined-0/+3mm

S45C forged round steel

S45C Forged Round Steel Bar

REQUEST FOR QUOTATION