Camlock Size Chart: Measure Once, Order Right
Camlock sizes describe the nominal bore of the hose or pipe the coupling fits — not the outside diameter of the fitting, and not the outside of the hose. A 2” camlock clamps onto 2” hose. That’s the whole trick, and it’s where most order mix-ups start.
Sizes Available
Standard cam and groove couplings are made in these nominal sizes:
| Size | Typical duty |
|---|---|
| 1/2” | Small lines, sampling, laboratory |
| 3/4” | Pilot plants, small pumps |
| 1” | Transfer skids, small pumps |
| 1-1/4” | Irrigation sub-mains |
| 1-1/2” | General transfer, fire reels |
| 2” | The workhorse — pumps, tankers, irrigation |
| 2-1/2” | Larger pumps, tanker offload |
| 3” | Tanker loading, dewatering |
| 4” | Bulk transfer, manifolds |
| 6” | Large bore bulk / dredging |
Aluminum and stainless are stocked 1/2” through 6”. Polypropylene runs 1/2” through 4”. Brass runs 1/2” through 4”.
The 60-Second Measuring Method
- Measure the hose bore (inside diameter) in inches. Most transfer hose is labelled — 2”, 3”, etc. Trust the label, verify with a ruler.
- For threaded ends, measure the thread: NPT vs BSPT. NPT is tapered, BSPT is parallel with a taper — they are NOT interchangeable. When in doubt, send us a photo of the thread end.
- Never mix sizes. A 2” adapter will not seat in a 2-1/2” coupler. The cams won’t reach the groove, and forcing it bends the arms.
Pairing Rules in One Line
Male adapters (A, C, E) mate with female couplers (B, D, F) of the same size. Same size, always. DC dust caps cap female ends; DP dust plugs plug male ends.
Metric Gotchas
Camlocks are an inch-world product. A “50 mm” coupling is usually the 2” size (50.8 mm nominal bore) — confirm the inch size before ordering metric hose. We also stock 25 mm and 63 mm variants on request.
FAQ
Is a 2” camlock the same as 2” hose? Yes — nominal bore matches. If your hose is labelled 2”, order 2” camlocks.
How do I know if my existing camlock is 1-1/2” or 2”? Measure the inside of the female coupler or the groove end of the male adapter. A 2” bore is roughly 50 mm across; 1-1/2” is about 38 mm.
Can I step between sizes? Yes — camlock reducers connect a larger coupling to a smaller hose. Size the coupling to the larger bore and the reducer steps it down.
Size and compatibility data are reference values from public industry sources, pending factory verification. Send a photo of your connection point and we’ll confirm the size before you order.