CHAIN TERMS
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.
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.
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 manufacturers 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

Grade 70 chain was specifically designed for the transportation industry. Grade 70 Chain typically has a 20% higher working load limit than High Test Chain or Grade 43 Chain.
G70 binder chains are also referred to as Tow Chains or Transport Chains, Spectrum 7 or System7. The increased strength of grade 70 chain allows for easier handling and the reduced
number of chains required by the North American Standard for Protection Against Falling and Shifting Cargo.
The Grade 70 binder/tow chains are supplied with a clevis grab hook on each end. Grade 70 Chain is NOT approved for overhead lifting.

All of our Laclede Grade 70 Binder/Tow Chains are Made in the USA. To help identify the grade and manufacturer all of our Grade 70 Chain is embossed withL7.
The L is the chain manufacturer Laclede. The 7 identifies this as a Grade 70 Chain. Grade 70 chain is typically finished with a Gold Chromate or Yellow Zinc. You will also find a trace code embossed on the chain.
This trace code provides Information about the manufacturing history of the chain as well as the origin of the steel. The code is a combination of letters and/or numbers located on Grade 100, Grade 80, and Grade 70 chain.

These grades are all heat treated. (A process that involves heating chain to extreme temperatures to harden the material and improve the metallurgical and tensile properties of the chain).
You will soon be seeing these tags on our most popular lengths of 5/16, 3/8, and 1/2 G70 assemblies. These new tags state the size, grade, working load limit, made in the U.S.A., and a not for overhead lifting warning.
This is NOT a requirement from the D.O.T. Laclede listened to your feedback and developed a tag so that inspectors could identify the grade and workload by quickly reading the information on the UV resistant tag.
Our chain will still be marked L7 and have the gold chromate finish. This tag will be yet another identifier for Lacledes Grade 70 domestic chain