Amazon.com, Grainger and Wal-Mart sell large worm gear hose clamps on their respective websites. HoseClampMan.com sells various sizes of hose clamps and hosts a chart showing standard American stainless steel worm gear hose clamp sizes.
The largest standard American worm gear hose clamp is the SAE size 56. This clamp adjusts from 3 1/16 to 4 inches in diameter. The second-largest standard hose clamp is the SAE size 52, which fits hoses from 2 13/16 to 3 3/4 inches in diameter. Screw-clamp, or worm gear, hose clamps are commonly used in household and automotive applications, and, in a pinch, several smaller screw-clamp hose clamps can be joined together to form a larger clamp.