Swivel eye is made of high strength forged steel and is fastened to head with a welded nut for positive security.
Two five-sixteenth (5/16) inch diameter steel roll pins, capped with tinner rivets, are used in closed head blocks.
The standard open head block has one five-sixteenth (5/16) inch diameter steel roll pin, capped tinner rivets, and one five-sixteenth (5/16) inch diameter steel detente pin. The detente pin is secured to the block with a length of welded steel chain.
The three (3) inch diameter free running sheave is profile machined to exacting tolerances for greater lifting efficiency. The shielded ball bearings are permanently lubricated and have a rating of 1250 pounds at a sheave speed of 100 rpm for an average life of 2500 hours at the rated loads and speeds.
Frame, head and sheave are cast from high strength A356-T6 Aluminum Alloy.
Five-eights (5/8) inch diameter steel axle is secured in frame by steel drive pins driven through each end of axle. Pins are positioned by recessed slots in frame to prevent rotation of axle.
Body frame halves are securely riveted together with a one-quarter (1/4) inch diameter drive pin and capped with tinner rivets.