D = 5/8 (See fig. 6-28)
D2 = 5/8 X 5/8= 25/64
SWL = 3 X 25/64 x 1 ton = 75/64 x 1 ton=1.1719
The SWL in pounds = 1.1719 x 2,000 pounds =
In the metric system, the formula for the safe
for shackles is as follows:
SWL = .417 X D2 X 1 tonne
D2= 1.59 X 1.59 = 2.52
SWL = .417 x 2.52 x 1 tonne
SWL = 1.05 tomes
NOTE: A hook or a shackle can actually lift more
than these formulas allow. These formulas give you
the safe working load UNDER ANY CONDITIONS.
Mouse shackles whenever there is danger of the
shackles pin working loose or coming out due to
vibration. To mouse a shackle properly, you take
several turns with seizing wire through the eye of the
pin and around the bow of the shackle. Figure 6-29
shows what a properly moused shackle looks like.
Figure 6-28.Shackle diameter.
Figure 6-29.Mousing a shackle.
Steelworkers are required to move and handle
many steel beams and steel shapes. When off-loading
steel from vehicles and storing for further use, beam
clamps are much more practical than using slings or
chokers, especially when the flanges are the only
available parts of the load. Figure 6-30 shows three
different types of beam clamps. View A shows a clamp
designed for use on a beam with a flat flange, either
an I or an H. The clamp in view B may be used on
beams with a circular cross-sectional area or where
only one side of the flange is accessible. View C shows
a clamp that is useful for connection to a column with
a snatch block attached. The clamps shown can all be
fabricated in the shop or field.
Hooks, shackles, and beam clamps must have the
rated capacities and SWL permanently stenciled or
stamped on them. OSHA identification tags can be
acquired at no cost from COMTHIRDNCB DET, Port
Hueneme, California, or COMSECONDNCB DET,
Gulfport, Mississippi. Metal dog tags are authorized
providing the required information is stamped onto the
OTHER LIFTING EQUIPMENT
Other devices used for moving equipment are as
follows: spreader bars, pallets, jacks, planks and
rollers, blocks and cribbing, and scaffolds.
Figure 6-30.Types of beam clamps.