AMS 6455
AMS 6455 is the SAE Aerospace Material Specification for SAE 6150 chromium-vanadium alloy steel in the sheet and strip product forms. Sheet and strip in thicknesses from 0.010 inch to 0.375 inch are covered in the annealed, normalized, or quenched and tempered condition. AMS 6455 flat product is primarily used for leaf spring blanks and formed spring components where the same outstanding fatigue resistance and hardenability of 6150 bar (AMS 6448) is required in a flat-rolled form suitable for blanking, forming, and heat treating to produce aerospace leaf springs, Belleville disc springs, and formed torsion members.
The sheet and strip form of 6150 is supplied annealed for blanking and forming operations; parts are heat treated and shot peened after all forming is complete to maximize surface compressive residual stress and fatigue life. Tight flatness and surface quality requirements in AMS 6455 ensure consistent part geometry and minimize stress concentrations from surface defects that would reduce the fatigue life of finished spring components.
AMS 6455 sheet in the annealed condition has a maximum hardness of 229 HBW for forming and blanking operations. After heat treatment to 190,000–200,000 psi, elongation is minimum 10% with adequate ductility to survive typical spring deflection strains without fracture. Shot peening per MIL-S-13165 or AMS 2430 after heat treatment is a standard process for aerospace leaf springs, introducing compressive residual stresses of 100,000–150,000 psi at the surface that directly offset the applied tensile fatigue stresses and extend the fatigue life by 3–5 times.
- Aircraft cantilever leaf spring elements
- Belleville disc washer springs for fastener preload
- Aerospace formed torsion spring strips
- Formed retaining spring clips for aerospace panel fasteners
- Heat-treated spring strip for aircraft control system components
Certified Material for Critical Service
AMS 6455 sheet certifications include chemical composition per heat including vanadium, mechanical properties per lot in the applicable condition, flatness and surface quality inspection, and dimensional certification. Spring manufacturers may additionally specify bend test results, surface roughness limits, and decarburization depth limits per the applicable aerospace spring standard. Material is traceable by heat and lot number throughout the manufacturing process.