6D34 Nitriding Heat Treated Crankshaft ME051714 — Forged Alloy Steel for Kobelco SK200-6 Excavator Engine Parts

Product Overview

The 6D34 crankshaft is the most heavily stressed component in your Kobelco SK200-6 excavator engine. SILK manufactures this critical part from forged 42CrMo alloy steel and applies a controlled multi-stage nitriding heat treatment process that achieves surface hardness of HRC 58-62 — matching or exceeding OEM specifications. Every crankshaft passes five inspection stages before release: ultrasonic flaw detection, CMM dimensional verification, dynamic balancing to ISO 1940 G6.3, surface hardness testing, and magnetic particle inspection.

Key Features

• Multi-Stage Nitriding Heat Treatment — Unlike conventional through-hardening, our nitriding process creates an ultra-hard, wear-resistant surface layer (HRC 58-62) while maintaining a tough ductile core. This dual property gives the crankshaft both surface wear resistance and fatigue strength — exactly what a diesel engine crankshaft demands.
• Forged 42CrMo Alloy Steel — Starting from forged billets, not castings. Forging aligns the grain structure of the steel along the crankshaft profile, delivering superior fatigue resistance compared to cast alternatives. 42CrMo alloy composition provides optimal chromium and molybdenum content for heat treatment response.
• Dynamic Balanced to ISO 1940 G6.3 — Precision balanced on a computerized dynamic balancing machine. Eliminates destructive vibration at operating RPM, protecting main bearings and extending engine service intervals.
• Five-Stage Quality Inspection — Ultrasonic flaw detection → CMM dimensional verification → Dynamic balancing → Surface hardness testing → Magnetic particle inspection. Complete inspection report available upon request.
• ISO 9001:2015 Certified Production — Every process from raw material certification to final packaging is documented and traceable.

Technical Specifications

The Nitriding Advantage

Standard induction-hardened crankshafts develop a hard surface layer only at the journal surfaces, leaving fillet radii — the highest stress concentration points — relatively soft and vulnerable to fatigue cracking. Our gas nitriding process treats the entire crankshaft surface uniformly, including fillet radii, oil gallery interiors, and counterweight faces. This comprehensive hardening coverage is why nitrided crankshafts consistently outlast conventional hardened alternatives in high-load diesel engine applications.

Packaging

Each crankshaft is treated with anti-rust VCI (Volatile Corrosion Inhibitor) coating, wrapped in industrial-grade protective film, and secured in a custom-fit export plywood case with high-density foam cushioning and desiccant packs. ISPM 15 compliant for international shipping.