AS/NZ 4177.4 (AS/NZ = Australian Standard / New Zealand Stand) refers to Long Link Trailer Safety Chain. The complementary transport specification is ADR-62/02 (ADR = Australian Driving Rules)
AS 2321 refers to calibrated Short Link Chain
DIN 766 (DIN = German Institute for Standardization), this standard is for calibrated and tested chains using Grade 3 material.
ISO 4565 (International Organization for Standardisation) or EN 24565 (EN = English National) or BS 7160 (BS = British Standard), these are all the same standard which covers anchor chains for small crafts.
Grade of Chain: NACM (National Association of Chain Manufacturers & ASTM (American Society for Test Materials) classify chains in various grades. The higher the grade, the higher the working load limit for the same size of chain. G30, G43, G70, G80, G100 and even G120 among the common chain grades. The number after each letter is N/mm2. For example, G80 means that the maximum stress on the chain at ultimate strength is 800 newtons per millimeter squared.
Working Load Limit (WLL): (rated capacity) Is the maximum working load that should be applied in direct tension to an undamaged straight length of chain. Typically, there is a safety factor (SF) as a multiple (e.g. 5X) which is related to the MBS or the product (e.g. WLL = MBS / SF)
Proof Test: (manufacturing test force) Is a term designating the minimum tensile force which has been applied to a chain under a constantly increasing force in direct tension during the manufacturing process. These loads are manufacturing integrity tests and shall not be used as criteria for service or design purpose.
Minimum Breaking Force: The minimum force at which the chain during manufacture has been found by testing to break when a constantly increasing force is applied in direct tension. Breaking force values are not guarantees that all chain segments will endure these loads. This test is a manufacturer’s attribute acceptance test and SHALL NOT be used as criteria for service and design purpose.
Overhead Lifting: The process of lifting that would elevate a freely suspended load to such a position that dropping a load would present a possibility of bodily injury or Property damage.