25
HOOK & CHAIN INSPECTION
Repeated use over a long period of time will cause the hooks and load chain to wear or elongate, and
corrosion and/or cracks may arise depending on the place and method of use. The hooks and load
chain are vital components of the hoist that must be within the permissible limits of the following
tables.
Hooks
Measure dimension “A” of the new hook with a slide calipers, and write it down for future reference.
The hook must be replaced immediately when one of the following limits are exceeded:
• When deformation is visually noticeable (elongation, twists, cracks, etc.)
• When the limits of Table 9 are exceeded and when dimension “H” has worn down more than 95%.
• When dimension “A” differs from the above recorded value of the new hook.
Rated load
Top hook
Bottom hook
A
Normal
H
A
Normal
H
Normal
Limit
Normal
Limit
250kg
300kg
500kg
28
27
25.7
23
23
21.9
1tw, 1t
32
31
29.5
28
27
25.7
2t
33
35
33.3
33
35
33.3
Load chain
Measure the sections of the load chain that come into contact with the load sheave with a slide cali-
pers. Replace the load chain when the limits of Table 10 are exceeded. The whole load chain must be
replaced even if one link is extensively worm or deformed.
Rated load
Type
Chain dia. 0 d (mm) Standard p (mm)
Limit 10 links (mm)
250kg
300kg
500kg
1tw
0 6.3
6.3
19.1
196
1t - 2t
0 7.1
7.1
21.2
218
Table 9
Table 10
