BowThe curved part of the shackle. The load hangs in it.
PinThe bar across the opening. It passes through both ears.
EarsThe two ends of the bow. Each has a pin hole.
ShoulderThe ring on the pin that stops against the ear.
Shapes and pins 7
Anchor shackleIts bow is rounded, wider than the gap between the ears.
Chain shackleA shackle with straight sides, shaped like a link of chain.
Screw pinA pin with a threaded end. It screws into one ear.
Round pinA plain pin with no thread. A cotter pin keeps it in.
Cotter pinA thin split pin through a hole in the end.
BoltA bolt used as the pin. A nut holds it in.
NutIt screws onto the end of the bolt and holds it in.
How this list was compiled: Every name checked on 2026-09-30 and kept only where at least two of these use it. (1) Wikipedia, Shackle, https://en.wikipedia.org/wiki/Shackle : bow (anchor) shackle and D (chain) shackle; the shackle body; a threaded pin; a pin shackle closed with a bolt, a securing nut and a cotter pin. (2) A construction training guide on basic rigging (2015), read as search passages on archive.org, https://archive.org/details/basicriggingmodu0000unse : screw pin anchor shackle, round pin chain shackle, screw pin chain shackle, safety shackle; the load sits in the bow of the shackle; the shoulder of the pin is in contact with the shackle body. (3) E. Hinz, The Complete Book of Anchoring and Mooring (2001), read as search passages, https://archive.org/details/completebookofan0000hinz : the bow in the anchor shackle and the chain shackle; screw pin, round pin, or bolt, nut and cotter pin. (4) A rigging field handbook (2007), read as search passages, https://archive.org/details/rigginghandbookc0000klin : shackle ears; shackle body; the shoulder of the pin; only the bow of a shackle. (5) A United States court record that reprints a shackle patent, https://archive.org/details/micro_IA40385010_2801 : the shackle bow and its ears. (6) Two rigging manuals read as search passages (archive.org riggingmanual0000cons and liftingtackleman0000dick): screw pin, round pin and safety type anchor and chain shackles. Licence: own work
The drawing: Drawn for this site on 2026-09-30 from plain geometry; no maker's tool, nothing traced. Licence: own work
How it works
A shackle is a U-shaped piece of metal closed by a pin across its opening. It is the connecting link in rigging. The second view shows its two shapes and three pins.
Read the full guide
Bow, ears and pin
The curved bar is the bow. Its two ends are the ears, and each ear has a hole. The pin passes through both holes and closes the opening. The shoulder is the ring on the pin that stops against the ear.
Shapes and pins
An anchor shackle has a rounded bow. A chain shackle has straight sides, like a link of chain. A screw pin threads into one ear. A round pin is plain and is kept in by a cotter pin. The third kind uses a bolt, a nut and a cotter pin.
Bow shackle is another name for the anchor shackle, and D-shackle for the chain shackle. The quiz takes either.
Questions and answers
What are the parts of a shackle called?
The curved bar is the bow. Its two ends are the ears. The straight bar that closes the opening is the pin, and the ring on the pin that stops against the ear is the shoulder.
What is the difference between an anchor shackle and a chain shackle?
The shape of the bow. An anchor shackle, also called a bow shackle, has a rounded bow. A chain shackle, also called a D-shackle, has straight sides and is shaped like a link of chain.
What is a screw pin shackle?
A shackle whose pin has a threaded end. One ear is threaded too, and the pin screws into it.
What holds a round pin in a shackle?
A cotter pin. The round pin has no thread, so a thin split pin goes through a hole in its end.