-5-
HOOKS
Refer to ASME B30.10, Safety Standard for Hooks. Inspect hooks and measure hook
throat opening at least once a month. Between regular inspections check visually daily
for deformation, distortion, twisting, damage, and missing or damaged hook latches.
Inspect as follows :
1. Measure hook throat opening from metal to metal of the hook as shown by dimension
N1 in Figure 2. DO NOT measure from latch to metal. Hook must be replaced when throat
opening measurement has increased 5%, not to exceed 0.25 inch over the original throat
opening dimension of a new hook, as follows:
FIGURE 2
TABLE 2 - INSPECTION CHART
In chart, F indicates Frequent Inspection, P indicates Periodic Inspection
LOCATION
CHECK FOR
F
P
LOCATION
CHECK FOR
F
P
Braking mechanism
(See Page 4)
Slipping under load
Hard to release
Brake Parts
Brake Discs
Pawl; Ratchet
Pawl Spring
Glazing
Oil contamination
Excessive wear
Corrosion; stretch
Load Chain
(See Page 7)
Stretch
Excessive wear
Twist
Broken, cracked, or
damaged links
Deposits of foreign
material
Inadequate lubrication
Hooks
(See below)
Chemical damage
Cracks
Deformation
5%, not to exceed 0.25 inch
in excess of normal throat
opening
Any twist from plane of
unbent hook
Cracks (dye penetrant,
magnetic particle, or other
suitable detection method)
Hook Retaining
Members (Pins,
Bolts, Nuts)
Hook Latch
Suspension Members
(Sheaves, hand-
wheels, chain
attachments,
suspension bolts
or pins)
Bearing; Shafts
Gears
Load Block;
Suspension Hsg.
Trolley; Supporting
Structure
Bolts, Nuts, Rivets
WARNING Label
Not tight or secure
Damaged; does not close
Excessive wear
Distortion
Cracks
Excessive wear
Distortion
Cracks
Inadequate lubrication
Distortion
Broken or worn teeth
Cracks
Inadequate lubrication
Distortion
Cracks
Possible inability to
continue supporting
imposed loads
Not tight or secure
Removed or illegible
For
maintenance
(replacement required)
maximum throat opening
MM
INCH
MM
INCH
MM
INCH
MM
INCH
MM
INCH
MM
INCH
N1x105% and N+0.25”
1/2
73
2.874
16
0.63
20
0.787
36
1.417
27.5
1.083
31
1.22
1.28
1
86
3.386
20
0.787
24
0.945
40
1.575
28.5
1.122
33
1.299
1.36
2
113
4.449
24
0.945
30
1.181
50
1.969
35
1.378
41
1.614
1.69
3
133
5.236
28
1.102
42
1.654
54
2.126
41
1.614
45
1.772
1.86
5
152
5.984
36
1.417
46
1.811
61
2.402
44
1.732
50
1.969
2.07
7
1/2
185
7.283
42
1.654
66
2.598
71
2.795
43
1.693
49
1.929
2.03
10
236
9.291
62
2.441
90
3.543
80
3.15
51.5
2.028
66
2.598
2.73
15
270
10.63
65
2.559
90
3.543
110
4.331
60
2.362
90
3.543
3.72
20
323
12.72
79
3.11
118
4.646
120
4.724
85
3.346
94
3.701
3.89
N1
CAPACITY
Ton
STANDARD HOOK DIMENSION
N
A
B
E
M
