15.3.3 Thimble

A thimble is a protective insert which is fitted to the eye of a sling leg at the time of manufacture. Thimbles are fitted where it is desirable to protect the eye from the worst effects of abrasion and point loading. Two common types of thimble are used in the construction of slings. The heart shaped thimble, which is used where sling legs are to attach to other fittings, and the reeving thimble, which is designed to permit the passage of one eye through the other so that the sling may be used in choke hitch. A similar protective inset, known as the stirrup or half thimble, is designed to protect the wire rope of a soft eye when the sling is used in choke hitch. (See Figure 15.3.5-1 )