Quality Control & International Certification - Full Quality Control from Steel to Finished Chains
We test quality at every step of chain making. We check raw steel, link forming, welding, heat treatment, surface coating, and final loading before shipping.
We supply chains for swings, lifting equipment, ships, and tire snow chains. We control each step to make sure your chains are strong, accurate, and safe.
Incoming Steel ---> Forming & Welding ---> Heat Treatment ---> Surface Coating ---> Proof Load Test ---> Shipping
Raw Material Quality Control
High-Grade Steel with Full Batch Traceability
A good chain starts with good steel. We buy steel only from qualified steel mills. We test every batch of raw steel before production starts.
What We Test on Raw Steel:
Chemical Composition Test: We check Carbon (C), Manganese (Mn), Silicon (Si), and Chromium (Cr) levels. This makes sure the steel has the right hardness and toughness.
Mechanical Property Test: We check Tensile Strength, Yield Strength, Hardness, and Elongation Rate.
100% Material Traceability: We stamp a batch number on every steel lot. You can trace every chain link back to its original steel mill heat number and test report.
In-Process Manufacturing Control
|
Production Step |
Key Inspection Items |
What We Make Sure |
|
Chain Forming |
Link diameter, inner pitch length, outer width |
Chains run smoothly over sprockets without jamming. |
|
Chain Welding |
Weld penetration, joint alignment, surface smoothness |
No weak welds, no open seams, no cracks. |
|
Heat Treatment |
Temperature, holding time, quenching hardness |
High load capacity, high fatigue resistance, and low wear. |
Welding & Heat Treatment Inspection:
Weld Sampling: We run destructive pull tests on weld samples every 4 hours.
Computerized Heat Treatment: We use automated furnaces to keep hardness stable across the whole batch.
Surface Finish & Corrosion Testing
|
Surface Treatment |
Recommended Application |
Corrosion Resistance Level |
|
Electro Galvanized (EG) |
Indoor use, light outdoor use |
Basic rust protection |
|
Hot Dip Galvanized (HDG) |
Heavy rain, farm, long-term outdoor use |
High rust protection (Long service life) |
|
Stainless Steel (304 / 316) |
Marine, chemical, food processing |
Maximum corrosion resistance |
|
Powder Coated |
Playground swings, outdoor furniture |
Smooth surface, no sharp edges, decorative colors |
|
Black Oxide / Self-Color |
Industrial machinery, indoor rigging |
Basic oil protection |
Salt Spray Corrosion Testing
We test surface coatings in our salt spray chamber according to ASTM B117 standards.
Test duration: 48h / 96h / 248h / 500h+ (based on customer order).
Inspection goal: Make sure the coating does not peel off or rust early in salt, water, or harsh chemicals.
Mechanical & Load Performance Testing
100% Load Testing Before Packing
Safety is the most important part of chain manufacturing. We test finished chain samples in our testing lab before packing.
Proof Load Test
We pull the chain with a controlled proof load force (usually 2x the Working Load Limit).
Goal: Confirm structural integrity and catch any weak weld points before sale.
Breaking Load Test
We pull chain samples until they break in a hydraulic test machine.
Goal: Verify maximum breaking strength and confirm the safety factor (e.g., 4:1 or 5:1).
Fatigue Testing
For lifting and hoist chains, we test cyclic stress over thousands of cycles.
Goal: Make sure the chain will not break under repeated daily lifting operations.
International Standards Compliance
We manufacture and test chains according to major global standards:
ISO 9001: Quality Management System Certified Factory
EN 818 Series: Short link chain for lifting purposes
NACM / ASTM A413: Carbon steel chain specifications
ASTM A391: Alloy steel chain requirements for lifting
DIN 766 / DIN 763: Calibrated and uncalibrated link chains
CE / RoHS / REACH: European market safety and chemical compliance