Composition & metallurgy

Alloy content varies from small microalloy additions to substantial Cr-Ni-Mo systems. Classification as low- or high-alloy depends on convention and governing standards.

Common grades and standards

SAE/AISI 41xx Cr-Mo, 43xx Ni-Cr-Mo, 86xx Ni-Cr-Mo, 51xx chromium steels; EN 42CrMo4 and 34CrNiMo6 are widely used engineering examples.

Typical applications

Gears, shafts, pressure components, fasteners, heavy machinery, oil and gas equipment, automotive driveline parts, aerospace hardware and power-generation equipment.

Engineering characteristics

Improved hardenability, fatigue strength, toughness, creep resistance or wear performance depending on alloy system and heat treatment.

Known manufacturers and producer regions

Japan — Nippon Steel, JFE, Daido; India — Tata Steel, JSW, SAIL; China — CITIC Special Steel, Baowu; Europe — Ovako, voestalpine, Saarstahl; United States — Nucor, Carpenter Technology and specialty bar producers.

Selection checklist

Confirm product form, design code, strength level, toughness/impact requirement, service temperature, corrosion exposure, weldability, forming route, heat-treatment condition, dimensional tolerance, inspection level and mill certification. Do not substitute a “similar” grade solely from a cross-reference table without checking the governing specification.

Element Folio engineering reference. Grade ranges are typical and may vary by standard. Verify the latest ASTM/ASME, EN, JIS, API or other governing specification and the mill’s current product data before procurement.