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Welding Locking Pin

Name: China Welding Locking Pin Manufacturers Suppliers Factory - Wholesale Welding Locking Pin
Brand: Lemar
SKU: 304574029

Material:Steel/Cast iron
Application:Welding&Assemble
Process:CNC Machining
Surface treatment:Normal/Nitrided
Type:3D
Brand:Lemar

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Products Description

The quick-locking pin (industry abbreviation: locking pin, positioning pin, PC locking pin) of the 3D flexible welding platform is a core connector of the D16/D28 series 3D flexible welding fixture table. It is used to lock the platform, angle iron, positioning block, and clamping module, enabling rapid workpiece clamping and positioning. It is the most widely used standard component in flexible welding fixtures.

Core Application
Designed to be inserted into the standard grid holes of welding platforms, this component expands internally upon tightening-driven by internal steel balls-to firmly lock the platform to the fixture, or one fixture to another. This mechanism effectively eliminates positional shifts caused by thermal expansion and vibration during welding, thereby guaranteeing precise dimensional repeatability. Installation and removal take mere seconds to complete; by serving as a direct replacement for traditional bolt-locking methods, it drastically reduces the setup and assembly time required for welding fixtures.

Mainstream Specifications

D28 series

Nominal Outer Diameter: 28 mm, H7 Precision Ground; Mating Platform: φ28 mm, H7 Reference Bore
Clamping Force: ≥50 kN (approx. 5 tons); Shear Resistance: ≥250 kN

D16 series

Nominal Outer Diameter: 16 mm, H7 Precision Ground; Mating Platform: φ16 mm, H7 Reference Bore
Clamping Force: ≥12 kN (approx1.2 tons)

Internal Structure and Locking Principle

The body of the Welding Locking Pin houses five evenly distributed, hardened steel balls (HRC 58–62):

Loosen the hex socket head / handle → The steel balls retract into the pin body, allowing the pin to be smoothly inserted into the circular hole on the fixture plate;

Tighten the head (a rotation of just 45°–60° with a wrench is sufficient to lock) → The internal tapered core presses downward, driving the steel balls radially outward to firmly wedge against the hole walls, ensuring self-centering locking with zero clearance or axial play;

Loosen in the reverse direction → The steel balls retract, allowing the pin to be directly withdrawn.

Materials and Surface Finishes

Pin Body: 45# Steel / 40Cr; Quenched and tempered to HRC 32–35 to ensure high toughness and prevent fracture.
Steel Balls: High-carbon bearing steel (hardened) for superior wear resistance and resistance to deformation under pressure.

Surface Treatments (3 Mainstream Export Options):

Nitriding (Premium Choice): Nitrided and blackened finish; resistant to high temperatures and welding spatter, rust-proof, wear-resistant, and non-stick (Standard specification for exports to Europe and North America).
Hard Chrome Plating: Bright chrome finish; offers exceptional rust resistance, ideal for use in humid workshop environments.
Blackening & Quenching: Economical option; a widely used domestic standard model offering excellent value for money.