Weld Nut Hexagon & Square Class 4 Carbon Steel Plain (DIN 928 / DIN 929)

The Weld Nut (commonly known as a projection weld nut, spot welding nut, resistance weld nut, DIN 928 square weld nut, or DIN 929 hexagon weld nut) is a specialized internally threaded fastener designed to be permanently fused onto metal sheets, stampings, and structural steel frames via resistance spot welding. Featuring raised welding projections (nibs) or a circular pilot spigot ring on its base, the weld nut channels electric current directly into the joint metal, creating a strong, homogeneous weld nugget without requiring access to the rear face during final product assembly. Our carbon steel weld nuts are manufactured in strict compliance with global ISO standards.

Technical Specifications of Hexagon & Square Weld Nuts

We produce both DIN 928 square weld nuts and DIN 929 hexagon weld nuts using highly weldable low-carbon steel (1008/1010, Q195, Q235B) in Class 4 and Class 8 strength ratings. The plain, unplated finish ensures maximum electrical conductivity and prevents toxic zinc fumes or weld spatter contamination during automated resistance welding processes.

Precision Cold Heading and Projection Stamping Process

At our specialized manufacturing facility in Handan, China, carbon steel weld nuts are forged with high dimensional consistency to ensure seamless operation in automated robotic feeding and spot welding lines:

• Multi-Station Cold Forming: High-speed automated former machinery cold-presses low-carbon steel wire rod into exact square or hexagonal body geometries with uniform density.
• Precision Projection Stamping: Welding nibs and pilot spigot rings are stamped under high pressure to ensure consistent projection height across every batch, guaranteeing uniform current density during resistance welding.
• High-Precision Internal Tapping: Automatic tapping spindles cut metric 6H internal threads, establishing clean thread entries that prevent weld slag buildup inside the nut core.
• Surface Cleaning & Anti-Rust Oiling: Degreasing and chemical washing remove surface impurities, followed by a light application of rust-inhibiting oil that preserves electrical weldability.

Industrial Applications of Resistance Weld Nuts

Weld nuts provide permanent internal thread anchors in sheet metal assemblies where rear-side nut access is impossible during final equipment setup:

• Automotive Body-in-White (BIW) & Chassis: Fused onto car door frames, seat tracks, battery tray brackets, and subframe assemblies for high-vibration structural bolting.
• Electrical Enclosures & Server Cabinets: Spot-welded onto sheet metal chassis walls to secure internal mounting rails, transformers, and power distribution units.
• Heavy Equipment & Agricultural Machinery: Permanently anchored onto engine covers, hydraulic fluid tank walls, and cab enclosures.

Quality Control and Export Packaging for Weld Nuts

Handan YiHao Fastener enforces strict Quality Assurance (QA) standards for all overseas export shipments. Inspection procedures include 100% thread plug gauge go/no-go checks, projection height tolerance verification, weld push-out/torque-out destruction testing, and metallurgical carbon content analysis.

All export orders are bulk packed in heavy-duty 25kg inner cartons with moisture-resistant VCI bags, neatly stacked on ISPM 15 compliant fumigated wooden pallets, and shrink-wrapped for safe ocean transportation.