Harrington Hoists and Cranes (G)NTH Trolley - Manual (Page 25)

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Table 5-3 Hoist Inspection Methods and Criteria
Item Method Discard Limit/Criteria Action
Bolts, Nuts and
Rivets Visual, Check with
Proper Tool Bolts, nuts, snap rings, split pins, and rivets should
not be loose, deformed, or corroded. Tighten or replace
as required.
Side Plates Visual Must be free of significant deformation Replace.
Track Wheel -
Tread Visual, Measure Diameter of the inside and outside tread surface
should not be less than the discard value shown in
Table 5-12. Replace.
Track Wheel - Gear Visual Teeth should not be cracked, damaged, or
excessively worn. Replace.
Suspension Shaft Visual, Measure Suspension shaft should not be bent. Diameter
should not be worn by 10% or more. Replace.
Warning Labels Visual Warning Labels should be affixed to the hoist (see
Section 1.2) and they should be legible. Replace.
Trolley-Hoist
Capacity Label Visual The label that indicates the capacity of the hoist
should be legible and securely attached to the
hoist. Replace.
Twisted Hook
Hook Swivel
Figure 5-1 Bottom Hook Checks
Table 5-4 Top Hook & Bottom Hook Dimensions
“k” Measured When New:
Bottom: ______________________
Product Code
Nominal "k"
Dimension*
inch (mm)
"u" Dimension
inch (mm)
"t" Dimension
inch (mm)
Standard Discard Standard Discard
NTH010 1.92 (48.8) 0.86 (21.8) 0.79 (20.0) 0.63 (16.0) 0.57 (14.4)
NTH020 2.36 (59.9) 1.18 (30.0) 1.06 (27.0) 0.87 (22.0) 0.78 (19.8)
NTH030 2.72 (69.1) 1.48 (37.5) 1.34 (34.0) 1.06 (27.0) 0.96 (24.3)
NTH050 3.06 (77.8) 1.87 (47.5) 1.69 (43.0) 1.38 (35.0) 1.24 (31.5)
* These values are nominal since the dimension is not controlled to a tolerance. The "k"
dimension should be measured when the hook is new - this becomes a reference measurement.
Subsequent measurements are compared to this reference to make determinations about hook
deformation/stretch. See Section 5.7, “Hooks - Stretch”.