Original Excavator Hydraulic Pump Gearbox Original Gear Shaft 3081085 for ZX330 ZX330-5A ZX330-5G

Case-hardened alloy steel​ - Surface hardened for wear resistance with tough core.

Chromium-molybdenum steel (SCr/SCM)​ - Common Japanese standard gear steel.

Nickel-chromium-molybdenum steel (SNCM)​ - For high-strength, high-toughness gears.

Carburized and hardened​ - Surface carbon-enriched for extreme surface hardness.

Precision forged steel​ - Grain flow optimized for fatigue strength.

Fine-grained forged steel​ - Uniform microstructure for consistent properties.

Shot-peened surface​ - Compressive stress layer to resist fatigue cracking.

Precision ground teeth​ - For low noise, high efficiency, and exact meshing.

Through-hardened alloy steel​ - For certain large, heavily loaded gears.

Induction hardened teeth​ - Localized hardening on critical tooth surfaces.

Tempered martensitic structure​ - Provides optimal balance of hardness and toughness.

High core toughness​ - To withstand shock loads without fracturing.

High surface hardness (58-62 HRC typical)​ - To resist pitting and abrasion.

Deep case depth​ - Ensures hardened layer withstands heavy contact stresses.

Clean steel (low inclusion)​ - High purity to prevent fatigue initiation sites.

Vacuum degassed steel​ - Minimizes gas pores for better durability.

Alloying elements: Cr, Mo, Ni​ - For hardenability, strength, and toughness.

Dynamic load rated​ - Material selected based on calculated dynamic tooth loads.

ISO 6336 / AGMA 2001 rated​ - Designed to international gear rating standards.

Excellent wear resistance​ - Against mating gear and bearing contact.

High bending fatigue strength​ - To resist tooth root breakage.

High contact fatigue strength​ - To resist surface pitting and spalling.

Good machinability in pre-hardened state​ - Before final heat treatment.

Dimensional stability after heat treatment​ - Minimal distortion.

Corrosion-resistant plating/coating​ - Some have phosphate or other coatings.

Copper or nickel plating option​ - For corrosion protection or run-in.

Magnetic particle inspected​ - For quality control of surface cracks.

Ultrasonically tested​ - For internal defect detection in forgings.

Batch traceability​ - Material heat number tracked for quality assurance.

Manufacturer-proprietary grade​ - Often a specific, optimized steel grade developed for heavy equipment.