Chains. Grade 70, 80 or 100. what do you have and why??

Author: CC

Aug. 06, 2024

56 0 0

Chains. Grade 70, 80 or 100. what do you have and why??

I believe that as the experienced ones that the newbies are looking to for advise on these subjects holds us to higher accountabilities.
This is a debate that shouldn't have any traction. People much smarter than all of us have analyzed this subject, created load securement grade alloys, and the FMCSA and their engineers have made rules based on these for us to follow.

You would be correct that I DO NOT have a degree in metallurgy. There is no specific metallurgy degree that I am aware of, it is a subject that is part of welding, machining, tool & die making, fabrication, engineering, etc.
I am NOT a machinist. I have a machine shop in my garage.
I am NOT a welder. I have several welders in my garage.
I am NOT an engineer.
I am NOT a mechanic.
I have designed & built several record holding dragsters. Every part of; chassis, transmissions, clutches...but I'm not a licensed mechanic.
I have a deep fundamental understanding of all of the above, so yes, what I say is anecdotal...to a point because I haven't actually performed the scientific experiments. But I am using the science that has been done to back up my statement.
I AM studying engineering in a "distance learning" capacity at this time, so I kinda know what I'm talking about.

Metallurgy is the study of the characteristics of the various types of metals and alloys. What properties are desired, and what properties are not wanted. To obtain the desired properties different alloys are added to the recipe.
ULTIMATE BREAKING POINT IS NOT THE ONLY THING TO LOOK AT!!! The intended purpose is not that simple.
How does it break?
Why does it break that way?
Is that acceptable or unacceptable for the application?
Is there a better alternative?

The people at your rigging supplier telling you that "as long as you don't exceed the WLL" have not been properly educated on the subject. I've talked to many that have told me the same thing, but simply put...they're wrong.
Don't believe me? Fine, go find a fully ticketed crane operator and tell him that your switching all his G100 lifting rigging for G70, just don't exceed the WLL.
Any of the operators I know, and that's quite a few as I'm sure it is for JD as well, will tell me to go F### myself! I don't know about south of the 49th, but in Canada it's not legal to lift with G70. Any crane op doing so would violate and probably void their

G100 chain has much higher WLL ratings than G70, yes I said that! G100 has different alloys than G70, making the tensile strength much higher. That makes it great for lifting, because that's what is required for the application, lifting=direct tensile forces.
We don't lift, we hold down. We don't apply direct constant tensile forces. We shock load the crap out of our rigging. When we hit bumps in the road, our chains loosen and over tighten in high frequency cycles that require elasticity strength (that's why the WLL is RATED lower, because it DOES over tighten and needs an exceed factor). Yes, you can occasionally bend G70 chain links. Ever hear the saying "it will bend, but won't break?" That's what we want, bent chains keep the load from ejecting. G100 doesn't bend, it breaks, nothing to stop the load from coming off the trailer.
I know that NACM guide says G100 is used for tie down, but there is a difference between "tie down" and what we call tie down which is why it's listed as "Transport G70", and it's because of the shock loading.
You want a good comparison, look at your wheel studs and lug nuts. High carbon steel, exceptional clamping force...obviously fantastic for the application. They make great head bolts too. Oh, but take that same high carbon steel stud and pull sideways...SNAP!!! High carbon bolts have poor shear characteristics, that's where Grade 8 bolts come into play. Tell your mechanic to use Grade 8 bolts for your head next inframe...he'll get a kick out of that.

Based on that, we CAN NOT advise using anything other that G70 for load security. The alloy recipe is the correct material for our application.
Yeah you can probably use G100 for years and never have a problem, until you do.
Yeah you can probably cut corners and not hang as many chains as required, until you need them.
I have been in a head on collision. The shock load forces are frickin incredible!
I've had coworkers break trailers, at road speed. The destruction and devastation was unbelievable!
Chains bent.
Chains broke.
The loads stayed on the trailers.
That's not anecdotal, I was there.

If your new or not sure what rigging you should buy...I agree, most DOT officers are a pain in the butt...but the engineers that researched, came up with, and wrote the rules for load security, they're engineers, and they're pretty frickin smart people.

FWIW, Paying attention to smart people has made me smarter, ymmv.

I know the IDIOT statement pissed some people off, it was supposed to. Remember, a kick in the ### is still a step forward!

JD I respect you as well.I believe that as the experienced ones that the newbies are looking to for advise on these subjects holds us to higher accountabilities.This is a debate that shouldn't have any traction. People much smarter than all of us have analyzed this subject, created load securement grade alloys, and the FMCSA and their engineers have made rules based on these for us to follow.You would be correct that I DO NOT have a degree in metallurgy. There is no specific metallurgy degree that I am aware of, it is a subject that is part of welding, machining, tool & die making, fabrication, engineering, etc.I am NOT a machinist. I have a machine shop in my garage.I am NOT a welder. I have several welders in my garage.I am NOT an engineer.I am NOT a mechanic.I have designed & built several record holding dragsters. Every part of; chassis, transmissions, clutches...but I'm not a licensed mechanic.I have a deep fundamental understanding of all of the above, so yes, what I say is anecdotal...to a point because I haven't actually performed the scientific experiments. But I am using the science that has been done to back up my statement.I AM studying engineering in a "distance learning" capacity at this time, so I kinda know what I'm talking about.Metallurgy is the study of the characteristics of the various types of metals and alloys. What properties are desired, and what properties are not wanted. To obtain the desired properties different alloys are added to the recipe.ULTIMATE BREAKING POINT IS NOT THE ONLY THING TO LOOK AT!!! The intended purpose is not that simple.How does it break?Why does it break that way?Is that acceptable or unacceptable for the application?Is there a better alternative?The people at your rigging supplier telling you that "as long as you don't exceed the WLL" have not been properly educated on the subject. I've talked to many that have told me the same thing, but simply put...they're wrong.Don't believe me? Fine, go find a fully ticketed crane operator and tell him that your switching all his G100 lifting rigging for G70, just don't exceed the WLL.Any of the operators I know, and that's quite a few as I'm sure it is for JD as well, will tell me to go F### myself! I don't know about south of the 49th, but in Canada it's not legal to lift with G70. Any crane op doing so would violate and probably void their insurance and most likely would never get any again.G100 chain has much higher WLL ratings than G70, yes I said that! G100 has different alloys than G70, making the tensile strength much higher. That makes it great for lifting, because that's what is required for the application, lifting=direct tensile forces.We don't lift, we hold down. We don't apply direct constant tensile forces. We shock load the crap out of our rigging. When we hit bumps in the road, our chains loosen and over tighten in high frequency cycles that require elasticity strength (that's why the WLL is RATED lower, because it DOES over tighten and needs an). Yes, you can occasionally bend G70 chain links. Ever hear the saying "it will bend, but won't break?" That's what we want, bent chains keep the load from ejecting. G100 doesn't bend, it breaks, nothing to stop the load from coming off the trailer.I know that NACM guide says G100 is used for tie down, but there is a difference between "tie down" and what we call tie down which is why it's listed as "Transport G70", and it's because of the shock loading.You want a good comparison, look at your wheel studs and lug nuts. High carbon steel, exceptional clamping force...obviously fantastic for the application. They make great head bolts too. Oh, but take that same high carbon steel stud and pull sideways...SNAP!!! High carbon bolts have poor shear characteristics, that's where Grade 8 bolts come into play. Tell your mechanic to use Grade 8 bolts for your head next inframe...he'll get a kick out of that.Based on that, we CAN NOT advise using anything other that G70 for load security. The alloy recipe is the correct material for our application.Yeah you can probably use G100 for years and never have a problem, until you do.Yeah you can probably cut corners and not hang as many chains as required, until you need them.I have been in a head on collision. The shock load forces are frickin incredible!I've had coworkers break trailers, at road speed. The destruction and devastation was unbelievable!Chains bent.Chains broke.The loads stayed on the trailers.That's not anecdotal, I was there.If your new or not sure what rigging you should buy...I agree, most DOT officers are a pain in the butt...but the engineers that researched, came up with, and wrote the rules for load security, they're engineers, and they're pretty frickin smart people.FWIW, Paying attention to smart people has made me smarter, ymmv.I know the IDIOT statement pissed some people off, it was supposed to. Remember, a kick in the ### is still a step forward!

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How to Choose the Right Chains for Lifting and Transport

When it comes to transporting or lifting your equipment, supplies, tools, or other materials, you have to be sure you&#;re using the right chains to secure your load. How much a chain can hold depends on the type of material it&#;s made out of and how much stress it can endure before breaking.

We&#;ve put together this guide on the various chain grades and what applications each is suited for to help ensure you use the correct chain for your transport or lifting needs.

What are industrial chain grades?

Chain grades describe the ultimate breaking strength or tensile strength of a given type of chain. The common chain grades used today are G30, G43, G70, G80, G100, and G120. The numbers in each grade are newtons per square millimeter and one tenth of the actual mathematical grades. For example, G70 grade chains have a breaking strength of 700 N/mm2 (newtons per square millimeter).

Grade 30 &#; These chains are general purpose and made from low strength carbon steel. They are commonly used for load securement in the agricultural, logging, and light construction industries.

Grade 43 &#; Made from stronger carbon steel than grade 30 chains, grade 43 chains are used for towing, logging, securing containers, and marine applications.

Grade 70 &#; Grade 70 chains are about 20% stronger than grade 43 chains and made from heat treated carbon steel that provides excellent strength and durability. They are commonly used for trucking and trailer tie downs, heavy load securement, and heavy towing.

Grade 80 &#; Grade 80 chains are made of an alloy steel mixture that makes them extremely strong and suitable for overhead lifting. They can also be used for heavy duty towing, rigging, and tie downs.

Grade 100 &#; With about 25% more strength than grade 80 chains, grade 100 chains are used primarily as a sling component for extremely heavy overhead lifting. They are also used for heavy duty rigging, towing, and construction applications.

Understanding the working load limit of your chain

In addition to knowing your chain grade, you also need to understand your chain&#;s working load limit. Working load limit is usually provided in pounds and refers to the maximum amount of tension that can be applied to an undamaged chain. The limit will vary within each chain grade, based on the diameter and shape of the chain.

If you want to learn more, please visit our website G100 Chain.

When choosing the best chain for a lifting application, it&#;s important to make sure the working load limit is sufficient to support the weight of the load plus any additional forces imposed by angles or hitch types. Usage, wear, twists, overloading, corrosion, alteration, and misuse all affect the working load limit of any chain. To ensure the chain is safe for continued use, it should be regularly inspected.