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SAE8720H Special Steel: Carburizing Rate Data
When specifying gear steel for heavy-duty transmissions or critical drive train components, case depth consistency isn't just a specification—it's a liability shield. SAE8720H special steel delivers documented, lab-verified carburizing performance that sets it apart from conventional nickel-chromium-molybdenum alloys.
Published research in SAE International technical papers demonstrates that SAE8720H achieves exceptional case-hardening efficiency. Under identical processing conditions, carbonitriding with advanced nitrogen sources increased the effective carburizing rate by approximately 20% at case depths around 0.75mm, with even higher gains for shallower cases compared to standard carburising methods.
This H-grade alloy steel maintains a precise chemical balance: 0.17-0.23% carbon, 0.60-0.95% manganese, 0.35-0.75% nickel, 0.35-0.65% chromium, and 0.20-0.30% molybdenum.
The nickel-chromium-molybdenum combination delivers through-hardening response while maintaining core ductility—critical for impact-loaded components.
When processed correctly, SAE8720H achieves:
Tensile strength: 500 MPa (minimum)
Yield strength: 330 MPa
Elongation at break: 25%
Fatigue strength: 240 MPa
Consistent Hardenability Across Heats
As an H-steel grade certified under SAE J1268, SAE8720H guarantees predictable hardenability bands. For engineers specifying heavy-duty transmission components where case depth uniformity determines service life, SAE8720H special steel delivers verified carburizing rates, certified mechanical properties, and field-proven reliability—not just brochure claims.
Published research in SAE International technical papers demonstrates that SAE8720H achieves exceptional case-hardening efficiency. Under identical processing conditions, carbonitriding with advanced nitrogen sources increased the effective carburizing rate by approximately 20% at case depths around 0.75mm, with even higher gains for shallower cases compared to standard carburising methods.
This H-grade alloy steel maintains a precise chemical balance: 0.17-0.23% carbon, 0.60-0.95% manganese, 0.35-0.75% nickel, 0.35-0.65% chromium, and 0.20-0.30% molybdenum.
The nickel-chromium-molybdenum combination delivers through-hardening response while maintaining core ductility—critical for impact-loaded components.
When processed correctly, SAE8720H achieves:
Tensile strength: 500 MPa (minimum)
Yield strength: 330 MPa
Elongation at break: 25%
Fatigue strength: 240 MPa
Consistent Hardenability Across Heats
As an H-steel grade certified under SAE J1268, SAE8720H guarantees predictable hardenability bands. For engineers specifying heavy-duty transmission components where case depth uniformity determines service life, SAE8720H special steel delivers verified carburizing rates, certified mechanical properties, and field-proven reliability—not just brochure claims.
