EN30B alloy steel (conforming to BS 970 standards) is a 4.25% nickel-chromium-molybdenum case-hardening steel. It is specifically engineered to offer high core toughness and excellent shock resistance when carburised. Unlike standard carbon steels, EN30B retains significant core strength even after hardening, making it the material of choice for heavy-duty components like transmission gears and high-load shafts.

Buyers across the automotive, aerospace, and heavy engineering sectors source EN30B alloy steel from Nifty Alloys because we provide fully certified, traceable materials. As a specialized stockist, we ensure you receive the precise grade required for critical applications where failure is not an option.

What is EN30B Alloy Steel?

EN30B is a high-grade nickel-chromium alloy steel characterized by its exceptional "hardenability" and toughness. It falls under the category of case-hardening steels, which means it is designed to undergo a surface hardening process (carburising) while maintaining a softer, ductile core.

The specific metallurgy of EN30B distinguishes it from standard carbon steels. While simple carbon steels rely almost entirely on carbon content for hardness, EN30B utilizes a significant addition of nickel (approx. 4%) and chromium. This combination allows the steel to achieve deep hardening profiles and resist fatigue under heavy cyclical loads.

It is frequently specified for components that must withstand high surface wear (requiring a hard case) and significant impact or shock loads (requiring a tough core). Its ability to be air-hardened in certain cross-sections also minimizes distortion during heat treatment compared to oil-quenching grades.