AMS 6382
AMS 6382 is the SAE Aerospace Material Specification for SAE 4140 chromium-molybdenum alloy steel sheet, strip, and plate. The specification covers flat-rolled product from 0.020 inch through 4.000 inches thick in the annealed, normalized, or quenched and tempered condition. Chemical composition, mechanical properties, surface condition, and flatness requirements are established by AMS 6382 for aerospace-quality 4140 flat products.
SAE 4140 sheet and plate to AMS 6382 is used where AMS 6345 (4130) sheet lacks sufficient strength, and where 4340-family plate exceeds strength and cost requirements. The 4140 composition provides up to 200 ksi tensile strength in the Q&T condition while retaining adequate weldability for repair welding and moderate forming operations. It is a common choice for structural housings, hydraulic manifold bodies, and machined structural plates in aircraft and missile systems.
AMS 6382 plate in the annealed condition has a maximum hardness of 241 HBW for machinability. When heat treated to the Q&T condition, tensile strengths of 150,000–200,000 psi are achievable depending on section thickness and tempering temperature. Plate thicknesses above 1.500 inch may exhibit lower through-thickness strength due to reduced quench severity at the core; procurement specifications should specify the required strength level and applicable section thickness for quality assurance purposes.
- Aerospace structural housings and bracket plates
- Hydraulic manifold bodies and valve blocks
- Aircraft ordnance structural plates and bulkhead sections
- Ground support equipment structural members
- Precision machined structural fittings from plate stock
AMS 6381 — 4140 Bar/Forging
4140 bar, forgings, and mechanical tubing for aerospace bolt blanks, shafts, and structural fittings up to 200 ksi.
AMS 6345 — 4130 Sheet/Plate
Lower-strength 4130 sheet and plate with superior weldability for formed and welded aircraft structural panels.
Certified Material for Critical Service
AMS 6382 material is certified to chemical composition, mechanical properties (tensile, yield, elongation), surface condition, and flatness requirements. Mill test reports document heat chemistry and mechanical test results for each lot. Ultrasonic inspection to AMS 2631 is available for plate used in fracture-critical applications. All material is traceable by heat and lot number through bar and plate rolling operations.