Chain Inspection & Maintenance Best Practices-Blog-TOPONE Chain Lifting

(For Grade 80 & Grade 100 lifting chains from TOPONE CHAIN, Xintai Taida Mirso Co., LTD)

High-strength round-link chains are the unsung heroes of mines, construction sites, shipyards and defence projects. The following program distills EN 818-2 (lifting chains), DIN 22252 (mining haulage chains) and our own TÜV-certified Grade 100 practice into simple, field-ready procedures.

1 | Why scheduled inspections are important

Safety factor control – Identify wear or cracks before the 4:1 design margin (Grade 100) is compromised.

Uptime & cost – A 15-minute inspection saves hours of downtime or a six-figure incident report.

Compliance – Records pass CE / ISO 9001:2015 audits and ensure compliance with EN, ASTM, NACM and local OH&S codes.

2 | Recommended inspection cadence

Type	Minimum frequency*	Competence required	Typical triggers
Initial	Before first lift	Qualified person	Incoming goods, after repair
Frequent	Each shift or daily	Trained operator	Heavy shock loading, abrasive service
Periodic	Monthly (severe use) to 12 months (normal)	Certified inspector	Statutory exam, third-party audit

3 | Visual inspection checklist

Checkpoint	Reject if…
Surface cracks (weld or bend zones)	Any visible line or hook-type indication under 10× magnifier
Corrosion / pitting	Red rust on >10 % area or any pitting >0.5 mm deep
Link geometry	Twist > 10°, bend > 5°, out-of-round > 4 % (EN 818-2 tolerance)
Wear flats	Reduction of nominal diameter dndₙ by 10 % for Grade 100, 12 % for Grade 80
Stretch	Gauge length of 5 links ₍l₅₎ > 1.03 × nominal (EN 818-2)
Illicit repairs	Weld build-ups, ground-out cracks or non-OEM paint

4 | Dimensional / wear measurement

Nominal size dndₙ	Max. wear on any link	Max. allowable pitch increase*
6 – 10 mm	0.6 mm (10 %)	3 %
11 – 22 mm	1.1 mm (10 %)	3 %
23 – 45 mm	2.3 mm (10 %)	3 %

5 | Maintenance best practice

Cleaning – After each shift, flush abrasive dirt; use pH-neutral solvent, not acid pickles.

Lubrication – Apply penetrating chain oil after cleaning; ensure oil reaches the weld crotch.

Corrosion protection – Galvanised or Mn-phosphate coatings withstand 1 000 h salt spray (ISO 9227) on our Grade 100 product range.

Storage – On racks in a dry, ventilated warehouse ≥ 5 °C; never in contact with standing water or chemical fumes.

Post-weld heat treatment (PWHT) – Where repair welding is allowed (e.g., mining haulage chain), normalise + temper according to DIN 22252 hardness range 350–390 HV10 .

6 | Record-keeping

Maintain a logbook or computerized CMMS record that documents:

Chain ID / batch / maker (TOPONE CHAIN serial + heat no.)

All inspection dates & findings

Measured diameters, gauge lengths, hardness (if noted)

Repairs or replacements

Inspector's name & qualification

Good records illustrate due diligence and inform lifecycle costing.

Conclusion

A systematic "inspect–measure–maintain" cycle, according to EN 818-2 and DIN 22252 standards, will keep Grade 80 and Grade 100 chains safely working at their rated Working Load Limit. Pair these procedures with genuine TOPONE CHAIN products—manufactured on nine TÜV-inspected lines—to realize maximum service life and minimum risk in every lift.

Chain Inspection & Maintenance Best Practices