A prehardened mold steel (311-345 HB / 33-37 HRC) with improved machinability

41X40 is a chromium-manganese-molybdenum grade designed for plastic mold industry. This grade is normally delivered in a prehardened condition at a hardness level of 33/37HRC. The grade has a fully homogeneous martensite-bainite microstructure. 41X40 grade has specific sulfur addition (0.060% typical) in order to increase strongly its machinability. Compared to AISI P20 grade, 30% increase in milling speed and 300% increase in drilling speed can be expected. At constant cutting speed, tool life is multiplied a least by 5 when replacing P20 by 41X40 grade.

41X40 is not suitable for polishing requirements.

This grade is typically used for:
1.Plastic injection molds for thermoplastics
2.Extrusion dies for thermoplastics
3.Compression molds

Chemical Analysis
Typical values (weight%)

C	S	P max	Si	Mn	Cr	Mo
0.4	0.060	0.012	0.3	1.5	1.9	0.2

Mechanical Properties
Typical values for plates air quenched and tempered (thickness 45 mm – 1.8”).

	Hardness	YS 0.2		UTS		Elongation	Reduction of area	Elastic modulus
	HB	MPa	ksi	MPa	ksi	%	Z%	GPa	ksi
Longitudinal direction	320	920	133	1075	156	9	40	205	29745
Longitudinal direction	320	900	131	1060	154	8	35	205	29745

Delivery Conditions
Typical delivery sizes

Thickness	Width
20 – 120 mm (.79″ – 4.7″)	1500 – 2500 mm (59 – 98.4″)
120 – 600 mm (4.7″ – 23.6″)	1500 – 2100 mm (49″ – 82.7″)