How to Identify Chain Grade?

Lifting Chain grades define the working load limit (WLL) and material strength of lifting chains. Using the wrong grade can lead to equipment failure or accidents. In this guide, you’ll discover:

• Key standards (ASME, DIN, ISO)

• How to read chain markings

• Field identification tricks without labels

• Why grade matters for OSHA compliance

Method 1: Check Permanent Markings (The Fastest Way)

All certified chains must have laser-etched or embossed markings indicating grade. Here’s how to decode them:

ASME B30.9 Chains (USA): Look for “G” followed by numbers.

Example: “G80” = Grade 80 chain (WLL 8,000 lbs per ¼ inch chain).

“T8”(Uses “T” prefixes)= Grade 80, “T10” = Grade 100.

DIN 763 Link Chain (German): Standard number DIN 763 (applicable standard for marking)

• ISO 1835: Round Steel Lifting Chains for General Purposes

• ISO 3077: High-Tensile Lifting Chains

• ISO 3056: Chain Slings

Pro Tip: Use a magnifying glass if markings are worn. Avoid unmarked chains—they likely fail safety standards.

Method 2: Color Coding for Quick Identification

Some manufacturers add color tags or painted links for visual grading:

Grade 30 (G30): Green

Grade 70 (G70): Gold/Yellow

Grade 80 (G80): Blue

Grade 100 (G100): Red

Note: Colors vary by brand. Always cross-check with markings.

Method 3: Material and Manufacturing Clues

Chain grade correlates with material strength and manufacturing processes:

Low-Grade Chains (G30-G43): Made from carbon steel, used for non-critical tasks like towing.

High-Grade Chains (G70-G100): 8620 Alloy steel , heat-treated for strength. Common in cranes and hoists.

Grade 120+: Electro-slag refined (ESR) steel, used in mining and heavy industry.

Method 4: Test Certificates & Documentation

Request test certificates from suppliers. Legitimate chains include:

Certificate of Conformance (CoC): Confirms grade and ASME/DIN compliance.

Mill Test Report (MTR): Details chemical composition and tensile strength.

Red Flag: Suppliers refusing to provide certificates may sell counterfeit chains.

Method 5: Destructive Testing (For Unmarked Chains)

If markings are illegible, labs can perform:

Hardness Testing: Grade 80 chains have a Rockwell hardness of HRC 38-42.

Tensile Testing: Measures break strength (e.g., G80 chains = 80,000 psi minimum).

Warning: Testing destroys the chain—only use this method if replacements are available.

Common Mistakes to Avoid

Assuming All Chains Are Grade 80: 60% of chain failures stem from incorrect grade assumptions.

Ignoring Corrosion: Rust can reduce grade capacity by 30%.

Mixing Grades: Never connect different-grade chains—the weaker link determines total WLL.

FAQs About Chain Grades

Q: Can I use a higher-grade chain to increase WLL?

A: No. WLL depends on the weakest component in the system (e.g., hooks, slings).

Q: How often should I inspect chain grades?

A: OSHA mandates annual inspections, plus checks before each use in harsh environments.

Q: What’s the difference between Grade 80 and Grade 100 chain?

A: Grade 100 chains have 25% higher WLL and better fatigue resistance.

Why Chain Grade Matters: Real-World Examples

Case Study: A warehouse replaced G80 with G70 chains to save costs. Result: A 3-ton load caused chain failure, leading to $200K in damages.

Best Practice: Port of Rotterdam requires color-coded G100 chains for container handling—accidents dropped 45%.

Need Certified Chains? lieying supplies ISO/DIN-certified G70-G120 chains with traceable documentation.