SUJ2 Bearing Steel Multi-Step Precision Locating Core Pin

Multi-Step Stepped Core Pin Engineering

Multi-stage concentric stepped structure realizes integrated functions of product forming, axial positioning and limiting. The flat square tip avoids rotational slippage during workpiece indexing; smooth transitional shoulder eliminates plastic flow dead angle and weld lines during injection molding. Bottom slotted flange base enables quick positioning and bolt locking on mold plates and fixture bases, ultra-high coaxiality ensures consistent forming dimension after millions of mold opening and clamping cycles. Solid monolithic thick shaft body greatly improves bending resistance, resisting deflection under long-term ejection impact and high clamping pressure.

Ultra-Wear-Resistant SUJ2 Bearing Steel Construction

SUJ2 bearing steel delivers outstanding performance for long-cycle precision core pins:

• Full quenching heat treatment achieves ultra-high surface hardness, excellent anti-abrasion performance against repeated friction with plastic melts and workpiece contact
• Fine uniform grain structure maintains stable dimensional consistency under mold heating and cooling temperature cycles, no size drift after long-term production
• Mirror grinding eliminates surface micro burrs and unevenness, preventing scratch marks on high-gloss plastic product surfaces
• Good machinability to realize complex multi-step shoulder, flat tip and slotted flange integrated forming without secondary assembly Ideal for precision electronic plastic molds, cosmetic packaging molds and high-cycle automation indexing positioning stations.

Custom Core Pin Machining Support

• Custom shaft total length, each step diameter, flat tip thickness and flange slot size based on customer plastic product & fixture 3D CAD drawings
• Optional surface upgrades: Hard Chrome Plating, DLC Low-Friction Coating, Gas Nitriding Anti-Rust Treatment
• DFM mold consultation: stepped shoulder flow optimization, core pin strength reinforcement, ejection impact stress analysis
• Fast single-piece prototype sampling and mass batch interchangeable core pin delivery

Key Features & Advantages

1. Multi-Step Concentric Stepped Design: Integrated forming, positioning and limiting functions to reduce spare part types.
2. Anti-Slip Flat Square Tip: Prevents rotational offset during indexing and molding to guarantee consistent product appearance.
3. Full Mirror Ground Smooth Shaft: Low-friction surface reduces ejection resistance and avoids plastic surface scratch defects.
4. High Hardness Heat-Treated Bearing Steel: Extreme wear resistance extends service life for mass production molds and automation equipment.
5. Slotted Flange Quick Mount Base: Simplifies installation and disassembly for mold maintenance and fixture replacement.

Technical Specifications

Applications

Consumer Electronics Multi-Cavity Injection Molds

Stepped core pins for earphone shells, connector plastic housings and battery cover molds. Mirror smooth shaft produces flawless high-gloss electronic appearance parts, high hardness withstands long-cycle ejection friction.

Cosmetic Packaging Molding Tools

Small-size precision core pins for lipstick tubes, cosmetic cap internal forming molds, anti-slip flat tip ensures uniform inner contour of cosmetic packaging products.

Automotive Small Plastic Component Molds

Heavy-duty locating core pins for automotive wiring terminal plastic brackets, rigid anti-deflection shaft body maintains stable dimensional tolerance under high injection pressure.

Automated Assembly Indexing Fixtures

Multi-step positioning pins for robotic feeding and component indexing stations, ultra-high coaxiality guarantees micron-level positioning accuracy for high-speed assembly lines.

Medical Disposable Plastic Molds

S136 stainless steel alternative core pins for medical tube and syringe plastic molds, corrosion-resistant material meets medical hygiene standards and resists mold cleaning agent erosion.