—
10
—
7.3 Periodic inspection
Periodic inspection shall be made at the interval shown below and should follow the given procedures.
NORMAL (Normal use):
Semiannual inspection
HEAVY (Frequent use):
Quarterly inspection
SEVERE (Excessively frequent use): Monthly inspection
Figures in parentheses are Fig. No. in “PARTS LIST”. (Refer to page 27 to 32.)
Item
Inspection method
Discard limit/criteria
Remedy
Indications
Check visually.
WLL indication is clear.
Attach the name plate.
Hook
[1, 6, 55, 78]
(Top and bottom)
1. Deformation/
twist of hook
opening
Measure dimension “c” at
time of purchase with
slide calipers.
No deformation comparing with original
shape (at time of purchase).
Replace the hook.
Check visually.
Twist shall not be large enough to detect
visually.
Replace the hook.
2. Wear
Measure “a” and “b” with
slide calipers.
NEVER
use the hook if dimension “a” or
“b” becomes less than 90% of normal.
Replace the hook.
3. Hook flaw
Check visually.
No great damage permitted.
Replace the hook.
4. Hook movement
Turn hook.
Shall turn smoothly.
Replace the hook.
a (mm)
b (mm)
WLL
(t)
Normal Discard Normal Discard
0.5 17.0 15.3 12.1 10.9
1 21.8 19.6 16.0 14.4
1.5 26.5 23.9 19.5 17.6
2 30.0 27.0 21.8 19.6
2.5 33.5 30.2 24.3 21.9
3 37.5 33.8 27.2 24.5
5 47.5 42.8 34.5 31.1
7.5 63.0 56.7 47.5 42.8
10 63.0 56.7 47.5 42.8
15 80.0 72.0 50.0 45.0
20 90.0 81.0 56.0 50.4
