Hose clamps and band clamps are used to secure hose or flexible tubing to a fitting. The clamp is placed around the hose, directly over the fitting. As the clamp is tightened, it clamps the inner diameter of the hose to the fitting or barb.

Many different styles of hose clamps are available.

Band clamps feature a smooth inside diameter to provide a uniform clamping surface to prevent a leak path. The smooth diameter also reduces the risk of abrasion and puncture damage to soft hoses.

Ear clamps have ears on the perimeter of the clamp for tightening. Ears are crimped with a tool to tighten the clamp. 

Snap close or ratchet clamps are closed and tightened by a snapping or ratcheting mechanism. Tightening can typically be done by hand.

Spring hose clamps uses spring action to tighten. Using a tool, the clamp is expanded to fit into position. Once placed, spring action of clamp holds and secures in position.

T-bolt band clamps, or simply T-bolt clamps, are band clamps that use a T-bolt tightened by a hex-nut for sealing hose connections in air and liquid media applications. 

V-band clamps are circular clamps tightened by a screw. They have a "V" profile for drawing together two mating flanges.

Worm drive hose clamps have a worm drive type mechanism for tightening consisting of a screw and a series of slots in the clamp. As the screw is tightened, the threads engage the slots and tighten advance the band, tightening it onto the hose.

Although the types listed above are the most common, many other specialty clamp types are also manufactured.

Specifications

To ensure a tight seal and prevent leaks, hose clamps and band clamps must apply sufficient clamping force for the pressure inside the hose. The clamping force should be applied evenly around the diameter of the hose and the barb must be smooth and free of nicks, scratches, or contamination.

Hose clamps are manufactured to operate over a specified diameter range. It is important that the diameter of the hose to be clampled is within this operating range.

Other specifications to consider when selecting a hose or band clamp include band width and band material.

Hose clamps and band clamps are manufactured from many different materials. Carbon steel is the most common band material for hose clamps and band clamps. Stainless steel is the most common material when corrosion is a concern.

Other, less common materials include:

• Aluminum
• Brass
• Plastic

The video below illustrates the proper assembly of a band clamp using a punch style tool.

Band clamps. Video credit: Dixon Valve

Standards

MIL-SPEC AA-52506 — Covers metal hose clamps that are used for holding flexible ducts or hoses onto a male fitting. These hose clamps are generally used on coolant, fuel, oil, vacuum, and emission systems. The selection of type and size of hose clamps for a specific application involves factors, such as torque, vibration, and pressure requirements.

ISO 8177 — This international standard specifies maximum and minimum dimensions for omega clamps (saddle clamps) installed by means of two bolts with nominal diameters of 5 mm.

ASTM F2098 — Covers stainless steel clamps for securing SDR9 cross-linked polyethylene (PEX) tubing to metal insert and plastic insert fittings.

Image credit:

Advanced Technology Products