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About
Chain Grading
Chain strength is identified throughout our
website by
Working Load Limits* (WLL) - the higher the WLL,
the stronger the chain.
Chain Strength Chart
(Working Load Limit WLL
Comparison Chart)
Gr
30
Proof
Coil
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A
general purpose chain of standard commercial quality.
Made from low carbon steel, this chain is frequently used
for fabricating tow chains, logging chains and, when
appropriate, tie down or binding chains. Hallmarked every
3 feet or less on sizes over 5/16" with manufacturer's symbol and grade marking: 3,
30 or 300. Not for overhead lifting.
More info:
Order Here
Specifications Here |
BBB Anchor Chain |
A
compact (short) link chain of standard commercial quality.
Made from low carbon steel, this chain is used
primarily for boat windlasses when hot galvanized. Hallmarked every
link with "3B". Not for overhead lifting.
More info:
Order Here and
Specifications |
Gr
40
High
Test |
Strength levels are the same as Gr 43 but
the dimensions of the chain links are smaller using ISO
standards. Primarily used for boat windlasses, this grade has
become a standard for that industry. The Grade 40
designation was exclusively used by ACCO Chain until 2005 to
designate their High Test grade chain. They now use "43" in
keeping with the rest of the industry. The chain
is hallmarked "G4" on every link. Not for overhead lifting.
More info:
Order Here and
Specifications |
Gr
43
High
Test |
This
is a higher strength chain used for years in the trucking
industry for tie downs that meet DOT specifications. Made
from a higher carbon steel, its strength surpasses proof
coil working load limits, size for size, by a factor of 2 to
1. Hallmarked every 1 to 3 feet with manufacturer's symbol
and grade marking: 4, 40, 43 or 400. Not for
overhead lifting.
More info:
Order Bulk Here Order Assemblies Here
Specifications Here |
Gr
70
Transport |
As
its name implies Transport Chain is used primarily to tie
down loads on over-the-road equipment. The yellow
chromate (gold) plating makes it easily recognizable even
from a distance. Made from heat-treated carbon steel it has
about 25% more strength than high test chains. Hallmarked
every 1 to 3 feet with manufacturer's symbol and grade
marking: 7, 70 or 700. Not for overhead
lifting.
More info:
Order Bulk Here
Order Assemblies Here
Specifications Here |
Gr
80
Alloy |
The
first chain specifically designed for safety and approved
by OSHA and other agencies for overhead lifting. Its
alloy, heat-treated steel makes it ideal for making lifting
slings and heavy duty tow chains. Hallmarked no more
than 3 feet apart with manufacturer's symbol and grade marking: 8,
80 or 800.Suitable for overhead lifting.
More info:
Order Bulk Here
Order Assemblies Here
Order Slings Here
Specifications Here |
Gr
100
Alloy |
This
new innovation in alloy chain metallurgy provides about 25%
higher working load limits over Gr 80 chain with some
limitations reported in lower ambient temperatures. Hallmarked
no more than 3 feet apart with
manufacturer's symbol and grade marking: 10 or 100.
Listed as suitable for overhead lifting.
More info:
Order Here Order Slings Here
Specifications Here |
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*WLL is sometimes called Safe
Working Load (SWL)
THE MEANING OF
CHAIN GRADE NUMBERS
The chain grade numbers which manufacturers use are actually one
tenth of the actual grades. Therefore, our grade 80 is 800, grade 70
is 700, and so on.
The grade refers to the tensile
strength of the chain. This is expressed in newtons per square
millimeter (a newton is approximately 0.224805 lbs). The tensile
strength is calculated by multiplying the grade times the area of
the two cross sections of a link (see below).
(Area) 157.08 mm2 x 800
n (Grade)=125,664 newtons ultimate breaking strength
125,664 newtons x .224805=28,250 lbs ultimate breaking strength
125,664 newtons÷1000=125.66 kn (Kilonewtons)
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