Case Study: Ultra-Low-Temperature Tungsten Carbide Studs for Nordic Winter Safety Footwear

Customer Background

A Swedish footwear manufacturer specializing in urban winter commuter boots and detachable crampons. The company produces over 120,000 pairs of injection-molded winter shoes per month, sold through major retailers across Scandinavia.

The Challenge

• Low-temperature brittleness: Standard carbon steel studs became brittle below -25C, fracturing on impact with asphalt and black ice.
• Rapid wear: Studs wore flat within 1-2 months, leading to high return rates and customer complaints.
• Molding defects: Inconsistent stud outer diameter caused frequent mold jamming during automated rubber injection, resulting in 14% scrap rate.
• Detachment: Sharp-edged studs pulled out of the rubber sole, leaving holes that let in water.

Our Solution

• Material customization: Developed a YG6X ultra-fine grain tungsten carbide grade with optimized cobalt content, balancing low-temperature toughness and surface wear resistance.
• Precision grinding: Centerless grinding with full sorting inspection — stud outer diameter controlled to high precision, ensuring seamless automated injection.
• Rounded tip profile: Optimized the tip radius to reduce stress concentration at the rubber-metal interface, preventing pull-out during walking.
• Anti-corrosion coating: Added surface treatment to prevent rust expansion in the wet winter environment.

Results

• Zero brittle fracture in field testing at -30C
• 14% scrap rate reduced to near zero — automated injection lines run smoothly with consistent stud dimensions
• Return rate dropped significantly — studs last the full winter season
• Customer has maintained exclusive supply agreement for 3 consecutive years