Connection type
Locking-nut drip fittings: NUTLOC, Smart Loc, Orbit, Perma-Loc
Locking-nut fittings pair a barb with a nut or collar, so ID and OD both matter. NUTLOC, Smart Loc and Orbit 67466 ranges, pressures and steps.
Also listed as spin-lock, nut-lock, universal fitting, Perma-Loc, Smart Loc, NUTLOC
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Short answer
A locking-nut fitting pairs a barb inside the tubing with a nut or collar over the outside, so both ID and OD matter. DIG lists NUTLOC for .530, .600 or .620 in ID (.630-.710 in OD) up to 60 PSI, Raindrip's Smart Loc for three ID x OD pairs up to 50 psi, and Orbit's 67466 for .620-.710 in OD. Perma-Loc is Irritec's line. See universal fittings explained.
Key facts
- How it grips
- A barb inside the tubing plus a nut or collar over the outside: Raindrip Smart Loc uses a barb and twist-on nut, Orbit 67466 a hand-twisted outer nut, Mister Landscaper MLF fittings a locking collar with built-in O-rings[1][2][3]
- Dimension that decides fit
- Both ID and OD: DIG lists NUTLOC by ID (.530, .600, .620 in) and OD (.630-.710 in); Raindrip lists ID x OD pairs[4][1]
- Ranges makers state
- DIG NUTLOC: .630-.710 in OD. Orbit 67466 and 67468: .620-.710 in OD. Raindrip S5600UB: .520 x .620, .600 x .700 and .620 x .710 in[4][2][5][1]
- Reuse and removal
- Orbit 67466: reusable; loosen the nut to remove the tubing. Mister Landscaper MLF: reusable locking-collar fittings[2][3]
- Meets directly
- 1/2 in poly tubing whose ID and OD fall in the stated range, for example Raindrip 062010P (.620 x .710 in) in Smart Loc[1][6]
- Needs an adapter to meet
- Not confirmedNo thread or OD adapter for locking-nut fittings is in our sources.
- Common mistakes makers name
- Drip Depot's Perma-Loc steps: do not remove the swivel collar; twist it back, push the tubing over the barb until it is covered (about 0.5 in), then tighten. Drip Depot also says Perma-Loc fittings for drip tape and for poly tubing are not interchangeable[7][8]Retailer guidance for Perma-Loc only. Perma-Loc is Irritec USA's fittings and valves line.
- Not confirmed
- Not confirmedNo wall-thickness range for DIG NUTLOC was confirmed. Perma-Loc sizes come from a retailer, not Irritec. Orbit states no pressure rating on the 67466 page we read.
Watch out for
- 'Universal' is a name, not a fit: each maker states a range, and the ranges differ (NUTLOC from .630 in OD, Orbit from .620 in).
- Raindrip's Smart Loc lists three exact ID x OD pairs, not a continuous range.
- Drip Depot says Perma-Loc fittings for drip tape and for poly tubing are not interchangeable.
- Drip Depot says to twist the Perma-Loc collar back rather than remove it.
What fits
Product details below are the seller's own description unless a source is shown. Pick the variant named for each item.
Smart Loc coupling
Raindrip Smart Loc S5600UB universal coupling (0.620, 0.700 and 0.710 in OD)Choose the S5600UB coupling.
Three pairs: .520 x .620, .600 x .700 and .620 x .710 in, up to 50 psi.
Smart Loc tee
Raindrip Smart Loc S5500UB universal tee (0.620, 0.700 and 0.710 in OD)Choose the S5500UB tee.
Same three Smart Loc pairs.
Orbit nut-lock coupling
Orbit 67466 1/2 in universal drip coupling (0.620‑0.710 in OD)Choose the 67466 coupling.
.620-.710 in OD; loosen the nut to remove the tubing.
Questions
Why do locking-nut fittings list both ID and OD?
The barb sits inside the tubing and the nut closes over the outside. DIG lists NUTLOC by ID (.530, .600, .620 in) and OD (.630-.710 in), and Raindrip lists ID x OD pairs.[4][1]
Can I reuse an Orbit 67466?
Orbit calls it reusable: loosen the nut to remove the tubing.[2]
How do Perma-Loc fittings go on?
Drip Depot says not to remove the swivel collar: twist it back, push the tubing over the barb until covered (about 0.5 in), then tighten it. See tubing popping off or leaking.[7]