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Item Inspection Methods Discard limit/criteria Measures
3. LOAD CHAIN
(1) Appearance
Check visually.
・ Load chain shall be oiled.
Supply oil.
(2) Wear Measure with
calipers.
・ Dimension “P” or “d” shall be
within the following values:
Replace.
Unit (mm)
Chain
diameter
(d)
Number of measured
chain links
Sum of pitches (P) of
measured chain links
Wear limit
of d
Normal Discard
4 5 60.5 61.7 3.3
(3) Load chain
Appearance
Check visually for
greasing and twisting.
Load chain is well lubricated.
If chain is dry, apply
the specified
lubricant in the
section ‘3.2(4)’.
Load chain is not
twisted or capsized.
If chain is twisted,
untwist it and restore
it to normal chain
condition.
4. HOO
S
(1) Deformation
Check visually.
・ No deformation from original
shape (at time of purchase).
Replace.
Measure dimension
“e” between two
embossed marks at
time of purchase with
calipers.
・ No deformation from original
shape (at time of purchase).
・ Never use the hook if dimension
(c) or (d) becomes less than 90%
of normal
Replace.
Measure with
calipers.
・ Dimensions “c” and “d” are within
their limits.
Replace.
(Reference values)
a mm
m
cmm d m
ormal
size
ormal
size
or
al
size
Discar
limit
ormal
size
Discar
limit
Bottom hoo
31.0 25.0 17.0 15.3 12.1 10.9
Top hoo
26.5 25.0 17.0 15.3 7.0 6.3
480
kg
Bottom hook
28.0 24.0 23.5 21.0 17.5 16.0
Top hook
Top hook
Bottom hook