Cam and groove fittings, also called camlock fittings or cam lever couplings, connect and disconnect hose and pipe in seconds without tools. This guide covers how they work, the standard types, how sizing works, how to measure a fitting you already have, and how to choose a material and gasket.
How Cam and Groove Fittings Work
Every connection has two halves. The male adapter has a groove cut around its end. The female coupler has two cam arms and a gasket inside. When the arms are pressed down, the cams pull the adapter into the coupler and seal it against the gasket. The arms lock in the closed position, and many couplers have safety pins or locking arms for added security.
- To connect: slide the adapter into the coupler and press both cam arms down by hand.
- To disconnect: lift the cam arms and pull the adapter out.
Because the groove runs all the way around the adapter, there is nothing to line up or cross thread.
Cam and Groove Fitting Types
Fittings are identified by a letter that describes the coupling end and the other end.
| Type | Coupling end | Other end |
|---|---|---|
| A | Male adapter | Female thread |
| B | Female coupler | Male thread |
| C | Female coupler | Hose shank |
| D | Female coupler | Female thread |
| E | Male adapter | Hose shank |
| F | Male adapter | Male thread |
| DC | Dust cap | Fits over a male adapter |
| DP | Dust plug | Fits into a female coupler |
Types A, E, F and DP are male. Types B, C, D and DC are female.
How Cam and Groove Sizes Work
The size of a cam and groove fitting is the size of its coupling end, the part that connects to the mating fitting. On most fittings the thread or hose shank is the same size, but not always:
- Reducing fittings have a different coupling size and connection size, such as a 2 in. coupler with 1-1/2 in. threads.
- Some small fittings have a larger coupling end. A fitting with 1/4 in. or 1/2 in. threads can have a 3/4 in. coupling end, and a fitting with 1-1/4 in. threads can have a 1 in. coupling end.
Product listings usually show the coupling size first, such as 3/4 in. x 1/2 in. When ordering, match the coupling size to the fitting you are connecting to, not just the thread or hose size.
How to Measure a Cam and Groove Fitting
Cam and groove sizes are nominal, so a fitting does not measure the same as its size. To identify a fitting, measure it with a caliper and find the closest match in the chart.
- Male adapter or dust plug: measure across the end of the fitting, at the rim beyond the groove. This is the widest part of the end that goes into the coupler. Do not measure inside the groove or across the threads or hose shank.
- Female coupler or dust cap: pull the gasket out of the bottom of the coupler socket and lay it flat. Measure across the outside edge of the gasket, straight through the center. The gasket is a plain ring with standard sizes, so it is an easy way to identify a female fitting.
| Size (in.) | Male end O.D. (in.) | Gasket O.D. (in.) |
|---|---|---|
| 1/2* | 15/16 | 1-1/32 |
| 3/4 | 1-1/4 | 1-3/8 |
| 1 | 1-7/16 | 1-9/16 |
| 1-1/4 | 1-25/32 | 1-15/16 |
| 1-1/2 | 2-3/32 | 2-3/16 |
| 2 | 2-15/32 | 2-5/8 |
| 2-1/2 | 2-31/32 | 3-1/8 |
| 3 | 3-19/32 | 3-23/32 |
| 4 | 4-23/32 | 4-7/8 |
| 6 | 6-15/16 | 7-1/16 |
| 8* | Under 9 | Varies |
*1/2 in. and 8 in. fittings have no interchange standard, so sizes vary by manufacturer. Contact us to confirm fit.
Are Cam and Groove Fittings Interchangeable?
Most cam and groove fittings are made to the A-A-59326 specification, which covers dimensions, materials and pressure ratings. Fittings made to it interchange across brands and materials in the same size, so a plastic adapter can connect to a metal coupler. The exceptions are sizes with no interchange standard, such as 1/2 in. and 8 in.
Pressure Ratings
Pressure ratings depend on size, material and type, and they drop as size goes up. Aluminum fittings from 3/4 in. through 2 in. are commonly rated 250 psi, while 8 in. fittings are rated 50 psi. In polypropylene, a 3/4 in. male adapter with a hose shank can be rated 300 psi and a 4 in. one 50 psi.
Ratings are given at 70°F. The male and female halves of a connection can have different ratings, and the connection is only as strong as the lower one. For example, if the adapter is rated 150 psi and the coupler is rated 300 psi, keep the line at or below 150 psi. For use above 70°F, contact us and we will check the rating with the manufacturer.
Choosing a Material
- Polypropylene: a cost-effective alternative to metal with good corrosion resistance. Common in industrial and agricultural use.
- PVC: available with solvent-weld sockets that cement directly onto PVC pipe. Weather and corrosion resistant.
- PVDF: strong and chemical resistant, with a wider temperature range than polypropylene.
- Aluminum: lightweight and strong for its weight. The most popular material for general industrial, petroleum, construction and irrigation use.
- 304 and 316 stainless steel: strong and corrosion resistant, and able to handle extreme temperatures. Used in food and beverage, chemical, marine, and oil and gas service.
For plastic fittings, check chemical compatibility with your fluid before ordering.
Choosing a Gasket
The gasket sits in the female coupler. Male adapters do not have one. Plastic couplers often come with EPDM gaskets and metal couplers with nitrile (Buna-N), and FKM and other materials are also available. Make sure the gasket is compatible with your fluid and temperature, and replace gaskets that are worn, cracked or flattened.
Safety Tips
- Do not disconnect a coupling under pressure or with liquid in the line.
- Close both cam arms fully. Use safety pins or locking arms where the fitting has them.
- Check the pressure rating before using a dust cap or plug on a pressurized line. Some are not rated for pressure.
Shop Cam and Groove Fittings
- All cam and groove fittings
- Polypropylene cam and groove fittings
- PVC and PVDF cam and groove fittings
- Aluminum cam and groove fittings
- 304 stainless steel cam and groove fittings
- 316 stainless steel cam and groove fittings
- Cam arms, pins and rings
Not sure which size or type you need? Contact us.
Frequently Asked Questions About Cam and Groove Fittings
Q: Is a camlock the same as a cam and groove fitting?
A: Yes. Camlock, cam and groove, and cam lever coupling are different names for the same type of fitting.
Q: Are cam and groove fittings interchangeable between brands?
A: Yes, in most sizes. Fittings made to the A-A-59326 specification interchange across brands and materials. 1/2 in. and 8 in. fittings have no interchange standard and may not fit other brands.
Q: What size cam and groove fitting do I need?
A: Match the coupling size of the fitting you are connecting to. To identify a fitting, measure the outside diameter of the male end, or of the gasket in a female coupler, and compare it to the size chart above.
Q: Which cam and groove types are male and which are female?
A: Types A, E, F and DP are male. Types B, C, D and DC are female.