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11
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Item
Inspection method
Discard limit/criteria
Remedy
5. Top/bottom fixture
damage
[Fittings of 1, 6, 55,
78]
Check visually.
No slack or missing rivets, nuts or bolts.
Replace the hook.
6. Idle sheave rotation
[57, 81]
Hold the load chain with
both hands and turn the idle
sheave by moving the chain
up and down.
Smooth rotation.
Overhaul.
7. Hook latch
[2, 7, 56, 80]
Check visually.
Proper positioning and smooth working.
Replace the hook latch or
hook.
Load chain
[47, 110]
1. Wear
Measure with slide calipers.
Measure the sum of pitches of five chain
links and check that the maximum length
does not exceed value shown in table
below.
Replace the chain.
2. Rust, flaw,
deformation
Check visually.
No obvious rust (Apply oil as necessary.)
Remove rust.
Check visually.
No twist or harmful flaw.
Replace the load chain.
Hook yoke
(Top set [1,54] )
(Bottom set [6, 77] )
Joint of top/bottom
fixtures with top pin [4]
and chain pin [8, 106]
Measure hole diameter of
joint area in two directions
at right angle.
Deformation not permitted (if each
measured value differs more than
0.5mm).
Replace the part.
One
pitch
Sum of pitches of five
links
WLL
(t)
Sum of pitches of five
links (mm)
Discard limit
(mm)
0.5 75.5 77.7
1 95.5 98.3
1.5, 3
106.0
109.1
2 121.0 124.6
2.5, 5, 7.5,
10, 15, 20
136.0 140.0
