In cotter pin puller tools, which form is common?

• A. S-shaped
• B. C-shaped
• C. U-shaped
• D. L-shaped

Answer: (A)

Cotter pins are split pins with two legs, so removing them requires grabbing both legs and pulling them apart with leverage. An S-shaped cotter pin puller is especially practical because its curved form provides two hook-like ends that can catch the two legs from a side angle in a single tool. You can slip one end under the head or between the legs, secure the other leg, and apply a controlled pull to extract the pin without banging into nearby parts. This shape works well in tight spaces and at awkward angles, where straighter or differently shaped pullers would struggle to maintain grip or alignment. That versatility and ability to engage both legs efficiently is why the S-shaped form is the common choice for cotter pin removal.