Need to invest in hose clamps? Here are a few important facts you need to know about the different kinds available on the market today.
Screw clamps, which are some of the more small hose clamps available, consist of a galvanized or stainless steel bands. These have a screw thread pattern which has been cut or pressed to make them more secure. The hose clamp is put around the tube to be connected, with the loose end being fed into a narrow space between the band and the captive screw to create a perfect seal. When the screw is turned, it acts as a worm drive pulling the threads of the band. This causes the band to tighten around the hose so that nothing leaks out. Screw clamps are normally used for hoses 1/2 in diameter and up, with other clamps used for smaller hoses where you do not need heavy duty hose clamps.
Wire clamps consist of a piece of heavy wire, typically steel, first bent into a tight U, then formed into a ring shape with one end overlapping the other, and finally the ends bent outwards and cut. A captive nut is attached to one end, and a captive screw to the other. When the screw is tightened, the overlapped ends of the wire are pushed apart, tightening the wire loop around the hose. For an explanation of why this design is used, see the section on sealing the connection.
One of the other popular hose clamps types are ear clamps. Ear clamps consist of a band, which is usually made of stainless steel, into which one or more ears or closing elements have been formed. The clamp is placed over the end of the hose or tube to be connected and when each ear is closed at the base of the ear with a special pincer tool, it permanently deforms, pulling the band, and causing the band to tighten around the hose. The size of clamp should be chosen such that the ear is almost completely closed on installation. This type of clamp was invented in 1921 by ex Royal Navy Commander, Lumley Robinson, who founded L. Robinson and Co (Gillingham) Ltd., a business in Gillingham, Kent.