| It is
important to inspect chain slings regularly and to keep a record
of individual chain inspection. The following is a suggestion
for such an inspection system. Before
inspection: Clean the chains so that marks, nicks,
wear and other defects can be seen. Each link should be
inspected for the following danger signs:
1. Twists
or bends
2. Nicks or
gouges
3. Excessive
wear at bearing points
4. Stretch
5. Distorted
or damaged master links, coupling links or attachments especially
spread in throat opening of hooks.
Each link or attachment
having any defect listed above should be marked with paint to
plainly indicate rejection and elimination from service until
properly repaired. |
|
Chain
requires only minimum maintenance:
1.
Store chains on a A-frame in a clean,dry place.
2. Oil chains
before prolonged storage.
3.
Never anneal chain |
Determine
wear by measuring cross section at link ends. If worn to
less than the minimum thickness allowable, chain should be removed
from service.
Chain
Size |
Diameter |
Maximum
Allowable
Wear |
Minimum
Allowable
Wire Diameter |
|
9/32" |
.281 |
.046 |
.235 |
|
3/8" |
.406 |
.078 |
.328 |
|
1/2" |
.531 |
.109 |
.422 |
|
5/8" |
.630 |
.140 |
.490 |
|
3/4" |
.787 |
.156 |
.631 |
|
7/8" |
.881 |
.171 |
.710 |
|
1" |
1.000 |
.187 |
.813 |
|
|
When the
chain itself is heated to temperatures shown below, the Working
Load Limits should be reduced as indicated. Grade
80 Chain
|
Temperature |
Reduction
of
Working
Load Limit WHILE AT Temperature |
Reduction
of
Working
Load Limit AFTER EXPOSURE
At Temperature |
|
(°F) |
(°C) |
|
Below |
Below |
|
|
|
400 |
204 |
None |
None |
|
400 |
204 |
10% |
None |
|
500 |
260 |
15% |
None |
|
600 |
316 |
20% |
5% |
|
700 |
371 |
30% |
10% |
|
800 |
427 |
40% |
15% |
|
900 |
482 |
50% |
20% |
|
1000 |
538 |
60% |
25% |
Over
1000 |
Over
538 |
OSHA
1910.184 requires all slings exposed to temperatures over
1000°F to be removed from service |
|
Greendale, WI 53129 