MIL-B-11595
MIL-B-11595 is the U.S. military specification for 4150 chromium-molybdenum alloy steel bars. It covers 4150 (UNS G41500) — a 0.48–0.53% carbon Cr-Mo alloy steel — in bar form for precision machined aerospace and defense components requiring maximum strength in the 4000-series alloy system. Tensile strengths up to 200 ksi are achievable in the quenched and tempered condition.
This specification defines chemical composition, mechanical properties, heat treatment requirements, and quality assurance provisions for 4150 bar procured for military aerospace and defense programs.
MIL-B-11595 covers 4150 alloy steel bar in diameters from 0.500″ to approximately 20.00″. Heat treatment: austenitize at 1550–1600°F, oil quench, temper at 300–1200°F. Typical Q&T properties at 900°F temper: 185 ksi UTS, 170 ksi yield, 12% elongation. Chemical composition per specification includes 0.80–1.10% Cr, 0.15–0.25% Mo.
- Aerospace Landing Gear Detail Parts
- Actuator Components and Hydraulic Bodies
- High-Strength Structural Fittings
- Military Defense Components
- Precision Machined Aerospace Parts
4150 Alloy Steel
4150 chromium-molybdenum alloy steel overview — properties, heat treatment, and applications.
SAE 4000 Series Alloy Steel
SAE 4000 series Cr-Mo alloy steels — 4130, 4140, and 4150 for aerospace and defense applications.
Certified Material for Critical Service
MIL-B-11595 material is supplied with full military certifications confirming 4150 chemical composition, mechanical test results in the required heat treatment condition, and complete heat-lot traceability per DoD specification requirements.