Tool Steel H11 AMS 6487

AMS 6487 is the aerospace material specification covering H11 tool steel (UNS T20811) bars, forgings and forging stock made by consumable electrode vacuum melting. After hardening and triple tempering at 1000°F minimum, it reaches around 260 ksi tensile and 215 ksi yield, and it holds that strength in service up to about 1000°F (538°C).

What defines AMS 6487 within the H11 bar and forging family is the vacuum arc remelt (VAR) step, and the fact that it’s the H11 bar spec that’s still active. Remelting the ingot under vacuum removes gases and most of the oxide inclusions that start fatigue cracks. That gives cleaner steel with better transverse ductility and more consistent fatigue life than the old air-melt grade. It’s why AMS 6487 replaced the cancelled AMS 6485 and AMS 6488 on most aerospace work.

Typical uses for AMS 6487 include:

• Landing gear pins, axles and fittings where fatigue life drives the design
• High-strength bolts and fasteners in the 260-300 ksi range
• Shafts and structural fittings that run hot near engines
• Forging stock for closed-die aerospace forgings

For H11 in sheet, strip or plate, see the companion specification AMS 6437. Full chemical composition, heat treatment and mechanical properties are on the H11 tool steel page. Tech Steel & Materials stocks and supplies AMS 6487 bar and forging to aerospace and defense tolerances. Request a quote for certified material cut to your size and quantity.