ENGINEERING
PRECISION LOCK NUTS

High-Performance Fastening Solutions Specializing in DIN 928/ISO 21670 Square Weld Nuts for Industrial-Grade Fusion and Absolute Thread Stability.

5M+

                        Annual Output

120+

                        Countries Served

7 Days

                        Sample Lead Time

99.9%

                        On-Time Delivery

ULTIMATE FASTENING STABILITY
& Expert Weld Nut Systems

High-precision anchors designed for permanent fusion in heavy-duty industrial applications.

◆ Longze leads the industry in providing advanced lock nut types, specifically the DIN 928 Square Weld Nuts. These are engineered for permanent fusion to metal sheets via resistance welding, eliminating the risk of nut spinning or loosening under high-torque assembly cycles.

◆ Our technical edge lies in the Balanced Projection Height (within ±0.05mm) and optimized weldability using lock nut types materials like C1008 low-carbon steel and Stainless 316, ensuring a high-strength fusion bond without compromising the internal thread tolerance.

CORE ENGINEERING
Technical Pillars

Three foundational pillars ensuring every weld nut delivers absolute reliability in mission-critical assemblies.

WELD PRECISION

Ensuring 100% contact and a balanced weld pool through precision engineering.

▸Projection Uniformity: ±0.05mm tolerance for identical boss height.

▸Pilot Centering: Precision-machined rings for robotic concentricity.

▸Thermal Control: Minimized Heat-Affected Zone (HAZ).

MATERIAL INTEGRITY

Premium alloys selected for weldability and extreme environment endurance.

▸Low-Carbon Steel: C1008/C1010 for superior weld flow.

▸Stainless Steel: Grade 304/316 for corrosive marine use.

▸Surface Purity: Plain/Oiled finish for zero porosity welds.

TOLERANCE RIGOR

Strict adherence to international standards for seamless integration.

▸Standard Compliance: ISO 21670 & DIN 928 precision.

▸Thread Class: 6H standard for effortless bolt entry.

▸Dimensional Accuracy: Zero deformation during cold-heading.

PERFORMANCE METRICS
& Analytics Data

Quantifying the reliability and material distribution of our fastener production line.

MATERIAL DISTRIBUTION

QUALITY ATTRIBUTES

TECHNICAL SPECS
Precision Data Sheet

Comprehensive mechanical properties and dimensional configurations for DIN 928 standards.

Thread Size (D)	Nut Width (s)	Total Height (m)	Pilot Dia (d2)	Proj. Height (h)	Material Grade
M4	7 mm	3.5 mm	5.0 mm	0.60 mm	C1008 Steel
M5	8 mm	4.0 mm	6.0 mm	0.70 mm	C1008 Steel
M6	10 mm	5.0 mm	7.5 mm	0.80 mm	Stainless 304
M8	13 mm	6.5 mm	9.5 mm	1.00 mm	Stainless 316
M10	16 mm	8.0 mm	11.5 mm	1.20 mm	C1008 Steel
M12	19 mm	10.0 mm	14.5 mm	1.40 mm	Stainless 316
M14	22 mm	12.0 mm	16.0 mm	1.50 mm	C1008 Steel
M16	25 mm	14.0 mm	18.5 mm	1.60 mm	Stainless 316

Real-World
Impact

Proven performance across diverse industries.

Global Auto OEM

                        CHASSIS COMPONENTS
                    

Implemented DIN 928 weld nuts for robotic assembly of chassis mounts, eliminating manual nut placement and reducing assembly time.

Efficiency: +25%

Defect Rate: Zero

Marine Equipment Co.

                        OFFSHORE PLATFORMS
                    

Deployed Stainless 316 weld nuts for saltwater-exposed electrical cabinets, ensuring long-term corrosion resistance and structural integrity.

Service Life: 30+ Years

Corrosion: Negligible

Steel Furniture Ltd.

                        HEAVY-DUTY RACKING
                    

Used carbon steel weld nuts for industrial shelving, optimizing the resistance welding process for high-speed production lines.

Weld Strength: High

Cycle Time: -15%

Industrial Enclosure Inc.

                        ELECTRICAL CABINETS
                    

Integrated precision weld nuts to ensure perfectly concentric threaded anchors for modular electrical panels.

Concentricity: Perfect

Fitting Rate: 100%

Industry
Applications

Tailored solutions for demanding environments.

Automotive OEM

High-strength weld nuts for chassis and engine components where zero-loosening is mandatory.

Marine Engineering

Stainless Steel 316 nuts for saltwater environments, preventing galvanic corrosion in ship hulls.

Medical Equipment

Passivated stainless nuts for surgical grade tables and equipment frames requiring sterility.

Industrial Racks

Low-carbon steel square nuts for high-speed resistance welding in heavy-duty storage systems.

Electrical Panels

Precision concentric nuts for automated housing assembly in industrial power cabinets.

Aerospace Fittings

Specialized high-tensile weld nuts for lightweight alloy structures in non-critical aerospace interiors.

Quality Assurance
& Export Standards

◈ Destructive Pull-Out Testing

We conduct rigorous "Push-out" and "Torque-out" destructive tests on every sample batch to verify weld fusion strength.

◈ Chemical Material Analysis

Spectrometric analysis ensures precise carbon content (0.08-0.13% for weldable steel) to prevent brittle joints.

◈ Thread Gauge Verification

100% verification using GO/NO-GO gauges to ensure all threads remain within 6H tolerance post-welding.

Trust Verified

Certified manufacturing processes ensuring full compatibility with global robotic welding lines.

✓ ISO 9001 Certified

✓ RoHS Compliant

✓ ASME B18.2.2

Frequently Asked
Questions

Expert answers to common technical and commercial inquiries.

Why choose square nuts over hex weld nuts?

Square nuts (DIN 928) provide a larger surface area for fusion and are significantly easier for robotic grippers to orient during the welding cycle compared to hex nuts.

Can these nuts be used with Imperial threads?

Yes, we manufacture 1/4", 5/16", and 3/8" UNC threads specifically for North American automotive and appliance projects.

What causes porosity in weld joints?

Welding through plating (like zinc) causes vaporization, creating gas pockets. We provide plain/oiled nuts to eliminate this risk.

How to avoid thread distortion during welding?

We recommend copper-alloy electrodes and optimized timing to prevent excessive heat from warping internal threads.

What is the recommended pilot hole size?

The pilot hole should be 0.2mm to 0.5mm larger than the nut's pilot diameter (d2) to allow for thermal expansion.

Do you provide sea-worthy packaging for export?

Yes, we use plastic-lined heavy-duty bags and palletized cartons to prevent flash rust during long-distance maritime transit.

ENGINEERING PRECISION LOCK NUTS

ULTIMATE FASTENING STABILITY& Expert Weld Nut Systems

CORE ENGINEERING Technical Pillars