Grade 70 Transport Chain
Transport chains are high strength chains used in applications where much strength is needed yet the task served is rather straightforward. Sometimes referred to as grade 70 binder chain, cargo chain, high-tensile chain, or trucking chain, this heavy-duty chain is designed for cargo control and tie down applications. Grade 70 chain is never to be used for overhead lifting. Drums of transport chain are available in lengths of 550’, 400’, and 200’, as well as custom-cut chain assemblies and chain tie downs.
How is Chain Grade Measured?
Chain grades are specified by the NACM (National Association of Chain Manufacturers) and the ASTM (American Society for Testing and Materials) standards that define the dimensional, mechanical, and compositional requirements that determine the proof of the steel, minimum breaking force required, elongation, etc. The combination of these measures determines the working load limit that each heavy duty chain can handle before risk of breakage. These factors are tested in a laboratory setting to ensure chain load capacity. Grade 43 chain, also known as High Test Chain, is a mid-grade cargo chain with a working load limit of 5,400 lbs for 1/2″ chain. Grade 70, referred to as Transport Chain, is top level of heavy chain with a working load limit as high as 11,300 lbs of cargo for 1/2″ chain.
Chain suppliers are required to clearly mark 5/16” and 3/8” chain links with their grade within 1 foot intervals along the truck chains, and within 3 foot intervals for ½” chain. This is to ensure easy identification and promote safety. It is very important to use the right heavy duty chain for the load you are transporting and these rules are D.O.T. enforced. The most common flatbed chains, hooks and binders are:
- Chain Binder or Load Binder
Also called a ratchet chain or ratchet load binder, this device uses a ratcheting action to tension chain and secure cargo. A ratchet binder consists of a ratchet handle and two tension hooks on each end.
Also called a lever chain or lever load binder. Chain-tensioning device uses a leverage action to tighten and secure loads. With a tension hook on each end, this binder requires more strength to tighten than ratchet binders.
- Grade 70 Chain Hooks
Clevis Grab Hook
Clevis grab hooks are very common on transport chain ends as the shallow throat opening allows for easy and secure connections. These hooks are designed specifically for grade 70 transport chain.
Clevis Slip Hook
Clevis slip hook, also referred to as a sling hook, is durable and features a wider throat than the clevis grab hooks. These hooks can be attached easily to grade 70 transport chains, and allow more versatility within your tie down assembly.
Clevis Slip Hook with Safety Latch
Clevis slip hook with latch, features a wider throat than a clevis grab hook; designed with a safety latch over the wide throat of the hook to ensure the chain is held in place. These slip hooks attach easily to grade 70 transport chain.
- Chain Extension
A short section of chain attached to the end of certain tie-down straps. These extensions include an eye grab hook on the end.
When to use Grade 70 Chain
When you need heavy chain to secure large loads grade 70 chain is the best choice. With the most efficient weight-to-strength ratio that comes from drop forging and heat treating, this truck chain allows you peace of mind that your load will be secured in place against sudden stops or tight turns where another transport chain could fail. Grade 70 chain and grade 70 chain hooks can be easily identified by their yellow zinc chromate finish and either 7, 70, or 700 embossed into the surface. Grade 70 chain strength is mandatory for auto transport chains, flatbed chains, heavy equipment chains, tractor tie downs, and log transport chains.
How Do I Choose a Lever Binder/Ratchet Binder?
When ordering lever binders or ratchet binders you will find that each size is determined with two measurements. There are two main grades of chain for tie-down applications, Grade 43 high test chain is used for stationary, non-transport tie downs and Grade 70 transport chain is for objects being transported on a flatbed or other moving vehicle. Each binder can be used with either size of equipment chain for the appropriate application, but since the different grades have different load limits each binder will be marked with the appropriate chain dimensions for both types of chain for proper performance. The first measurement (smaller) identifies the Grade 70 chain dimension, the second measurement (larger) identifies the Grade 43 chain size required.
Example: 5/16″ – 3/8″ Lever Binders; the 5/16″ specifies the chain binder can be used with 5/16″ Grade 70 Transport Chain or it can be used with 3/8″ Grade 43 High Test Chain (logging chain.) Small load binders can technically be used for both 5/16″ or 3/8″ chain in either grade, but if you pair this lever binder with 3/8″ Grade 70 transport chain the binder will be weaker than the chain, making the binder the weakest part of the assembly. If you are working with 3/8″ Grade 70 chain, the best option would be to pair it with a 3/8″ – 1/2″ Chain Binder so that the chain and binder are of equal strength. When choosing what grades of chain will go with what binders, be sure to consider both specifications.