Minimal Match — 32.8% match
based on chemical composition and mechanical property overlap.
JIS G4404 SKS31 (JIS G4404:2006) and GOST 5950 4H5MFS (GOST 5950-2000) are both steel grades.
Both fall under the Tool & Die Steels category.
JIS G4404 SKS31 is typically used for cold working molds, press dies, jigs, gauges, long taps, reamers, measuring tools requiring minimal quenching distortion., while GOST 5950 4H5MFS is commonly used for used for die casting dies, forging tools, extrusion dies, punches, and hot shear blades..
JIS G4404 SKS31 is defined under Japanese Industrial Standards (JIS) (Japan).
As per chemical composition, JIS G4404 SKS31 vs GOST 5950 4H5MFS is a 49.2% match.
As per mechanical properties, the match is 0%.
Combined, this makes them a minimal match overall at 32.8%.
Matched by chemical composition and mechanical properties, not a formal equivalence claim. Always verify against the applicable standard before substitution.
Mechanical Properties
Property
JIS G4404 SKS31
GOST 5950 4H5MFS
Tensile Strength
900-1150 MPa
1350-1650 MPa
Yield Strength
750 MPa min
1150 MPa min
Elongation
10% min
9% min
Hardness
58-62 HRC
44-50 HRC
Typical Applications
JIS G4404 SKS31
Cold working molds, press dies, jigs, gauges, long taps, reamers, measuring tools requiring minimal quenching distortion.
GOST 5950 4H5MFS
Used for die casting dies, forging tools, extrusion dies, punches, and hot shear blades.
Key Differences
JIS G4404 SKS31 specifies Mn, P, S, W which are not specified for GOST 5950 4H5MFS.
GOST 5950 4H5MFS specifies Mo, V which are not specified for JIS G4404 SKS31.
Can JIS G4404 SKS31 Be Substituted With GOST 5950 4H5MFS?
JIS G4404 SKS31 and GOST 5950 4H5MFS share some compositional similarity but differ enough that substitution should not be assumed. Review the differences above carefully, and consult the applicable standard or a metallurgist before using one in place of the other.
What is the difference between JIS G4404 SKS31 and GOST 5950 4H5MFS?
JIS G4404 SKS31 specifies Mn, P, S, W which are not specified for GOST 5950 4H5MFS. GOST 5950 4H5MFS specifies Mo, V which are not specified for JIS G4404 SKS31.
Can JIS G4404 SKS31 be substituted with GOST 5950 4H5MFS?
JIS G4404 SKS31 and GOST 5950 4H5MFS share some compositional similarity but differ enough that substitution should not be assumed. Review the differences above carefully, and consult the applicable standard or a metallurgist before using one in place of the other.