|
WORKING LOAD LIMIT
|
MINIMUM
ULTIMATE LOAD
|
| The
“Working Load Limit” is the maximum load
in pounds which should ever be applied to chain,
when the chain is new or “in as new” condition,
and when the load is uniformly applied in direct
tension to a straight length of chain. |
The
“Minimum Ultimate Load” is the minimum
load at which new chain will break when tested by
applying direct tension to a straight length of
chain at a uniform rate of speed in a testing machine.
|
|
PROOF
TEST
|
ATTACHMENTS
|
| The
“Proof Test” is a term designating the
tensile test applied to new chain for the sole purpose
of detecting injurious defects in the material or
manufacture. It is the load in pounds which
the chain has withstood under a test in which the
load has been applied in direct tension to a straight
length of chain. |
Any
attachments, such as hooks or links, should have
a rated “Working Load Limit” at least
equal to the chain with which it is used.
|
|
ANSI
/ ASME B30.9c-1994
|
CAUTION
|
| Paragraph
9-1.4.2 “Mechanically assembled slings shall
be comprised entirely of proof tested components.”
Paragraph 9-1.4.2c “If untested components
are employed, the sling shall be proof tested per
Para. 9-1.4.1 prior to initial use.”
|
•
Only Crosby Alloy chain, Spectrum 8¬,
should be used for overhead lifting applications.
• It must be recognized that certain factors
in the usage of chain and attachments can be abusive
and lessen the load that the chain or attachments
can withstand. Some examples are twisting
of the chain; disfigurement; deterioration by straining,
usage, weathering and corrosion; rapid application
of load or jerking; and applying excessive loads.
• Due to the crushing effect Grab Hooks have
upon chain, the design factor of all chain assemblies
must be reduced by 20% for the Grab Hook applications.
|
|
CHAIN
INSPECTION
|
|
TABLE 1
MAXIMUM ALLOWABLE WEAR AT ANY POINT OF
LINK
|
|
Normal Chain or
Coupling
Link
Cross
Section
|
Maximum
Allowable Wear Diameter
(in.)
|
|
9/32
|
.037
|
|
3/8
|
.052
|
|
1/2
|
.069
|
|
5/8
|
.084
|
|
3/4
|
.105
|
|
7/8
|
.116
|
|
1
|
.137
|
|
1-1/4
|
.169
|
|
REFER
TO ANSI B30.9 FOR FULL DETAILS
|
3.
Hooks should be inspected in accordance with
ANSI B30.10.
4. If present, latches on hooks should seat
properly, rotate freely, and show no permanent
distortion.
|
|
INSPECTION
AND REMOVAL FROM SERVICE PER ANSI B30.9
FREQUENT
INSPECTION
Normal Service - Monthly
Severe Service - Daily to Monthly
Check chain and attachments for
wear, nicks,
cracks, breaks, gouges,
stretch,
bend,
weld splatter,
discoloration from excessive temperature,
and
throat openings of hooks.
1.
Chain links and attachments should hinge freely
to adjacent links.
2. Latches on hooks, if present, should hinge
freely and seat properly without evidence of permanent
distortion.
PERIODIC
INSPECTION - INSPECTION RECORDS
REQUIRED
Normal Service - Yearly
Severe Service - Monthly
This inspection shall include everything
in a frequent inspection plus each link and end
attachment shall be examined individually, taking
care to expose inner link surfaces of the chain
and chain attachments.
1.
Worn links should not exceed values given in table
1 or recommended by the manufacturer.
2. Sharp transverse nicks and gouges should be rounded
out by grinding and the depth of the grinding should
not exceed values in Table 1.
|
|
Use
of Crosby Spectrum 8 Chain Under Heat Condition
|
Temperature
of
Chain |
Grade
80 |
Grade
100 |
|
(ÅF)
|
(ÅC)
|
Reduction
of Working Load Limit WHILE AT Temperature
|
Reduction
of Working Load Limit AFTER EXPOSURE
to Temperature |
Reduction
of Working Load Limit WHILE AT Temperature
|
Reduction
of Working Load Limit AFTER EXPOSURE to Temperature
|
Below
400 |
Below
204 |
None
|
None
|
None
|
None
|
|
400
|
204
|
10%
|
None
|
15%
|
None
|
|
500
|
260
|
15%
|
None
|
25%
|
5%
|
|
600
|
316
|
20%
|
5%
|
30%
|
15%
|
|
700
|
371
|
30%
|
10%
|
40%
|
20%
|
|
800
|
427
|
40%
|
15%
|
50%
|
25%
|
|
900
|
482
|
50%
|
20%
|
60%
|
30%
|
|
1000
|
538
|
60%
|
25%
|
70%
|
35%
|
Over
1000 |
Over
538 |
OSHA 1910.184 requires all slings exposed
to temperatures over 1000Å F to be removed
from service. |
*
All-Lifts, Inc. does not recommend the use
of Alloy Chain at temperatures above 800Á F.
** When chain is used at room temperature after
being heated to
temperatures shown in the first column.
|
|
