Sep 12, 2026Services Overview
Square link chain made from 20CrmnTi alloy steel
square link chain made from 20CrmnTi alloy steel
The most commonly used safety chains today are square link chains, though some applications also use round link chains or hexagonal link chains.
Safety chains are typically made from 20CrMnTi steel. Through heat treatment, the chain surface and a certain depth beneath it achieve higher hardness, providing anti-cutting protection.
20CrMnTi is the best choice for lock chains. That said, some opt for plain carbon steel or other alloy steels as alternatives, but their cut-resistant performance is not as effective.
Our most common surface finish for lock chains is electro-galvanized. Some customers also request PVC coating or a fabric sleeve, often with their brand name or logo printed on the sleeve.
Our safety chains are primarily used with locks — for bicycle locks, door locks, and even truck wheel locks. If you'd like to learn more about our lock chain products, feel free to contact us.
Sizes and Specifications
Our security chain is produced in sizes from 1/8 in up to 1 in diameter (3.2 mm to 25.4 mm), with test loads from 200 kg up to 12,150 kg and breaking loads from 400 kg up to 24,300 kg across the range, per our catalogue. Heat treatment is applied with or without depth hardening.
Finishes and Covers
Electro galvanizing is the standard finish for lock chains. PVC coating or a fabric sleeve is often added on top - the cover protects the surfaces the chain touches and can be branded for retail packaging.
Where Our Security Chains Are Used
Most of our square link security chains go into bicycle locks, door locks, truck wheel locks and similar security products, usually paired with a lock body from the customer's own production.
Frequently Asked Questions
Why is square link chain harder to cut?
The square profile presents a flat face to bolt cutters instead of the round section a cutter grips best, and the case-hardened surface resists the cutting edge. That is why it is the usual form for security chain.
What finish do your security chains have?
Electro galvanizing is the standard finish, with PVC coating or a fabric sleeve added where the chain must protect surfaces or carry a brand.
Is security chain suitable for lifting?
No. Security chain is made for locking and securing - it is not a grade-marked lifting chain and must not be used for overhead lifting.