Guide · Microtubing and connectors
1/4 in drip tubing is a family: .170 x .250 and the other sizes
Most 1/4 in poly drip tubing is listed near .17 in ID by .25 in OD, but vinyl, metric and some SKUs differ. The sizes each maker lists, and what to check.
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Picks that fit
- Raindrip 016010T 1/4 in black polyethylene supply tubing (0.170 x 0.250 in, 100 ft)Check price on Amazon
- Rain Bird T22‑50S 1/4 in blank distribution tubing (0.165 x 0.245 in, 50 ft)Check price on Amazon
- DIG B38PB 1/4 in polyethylene micro tubing (.170 x .250 in, 50 ft, brown)Check price on Amazon
Short answer
Most 1/4 in polyethylene drip tubing is listed at about .17 in ID by .25 in OD. Vinyl tubing and some single SKUs differ, and metric "1/4 in" is another pair of numbers again, so check the ID x OD of the exact roll against the barbs and stakes you plan to use.
Picks that fitAll picks and how to choose
Poly tubing: mostly .170 x .250
- Rain Bird XQ: polyethylene, 0.17 in ID by 0.25 in OD, rated 0 to 60 psi, for above or below grade.[1]
- DIG poly micro tubing: DIG's 2016 greenhouse catalog lists 1/4 in polyethylene micro tubing at .170 x .250 in, made of linear low-density polyethylene.[2] That catalog is dated, so check DIG's current page for a current SKU.
- DIG Microline dripline: .170 in ID by .250 in OD.[3]
- DIG G77AS kit: its manual lists B38P 1/4 in micro tubing with a .170 in ID.[4]
Rain Bird's XQ sheet also prints a wall thickness that does not agree with its own 0.17 and 0.25 in figures,[5] so go by the ID and OD. The same sheet calls XQ compatible with all 1/4 in transfer fittings; that is Rain Bird's marketing wording with no dimensions, so we do not repeat it as fit.
Vinyl tubing: several sizes
DIG's vinyl micro tubing table lists three 1/4 in sizes, .156 x .245, .160 x .220 and .170 x .250 in, plus a 1/8 in size of .118 x .187 in.[6] DIG's shop also lists one black vinyl SKU, 12-018, at .160 x .270 in in a 1,000 ft roll.[7] That size is for that SKU only; it is not on DIG's main vinyl table.
Mister Landscaper lists its 1/4 in vinyl tubing at .145 x .295 in.[8] With a smaller ID and a larger OD than poly, it should not be assumed to fit the same barbs and stakes as .170 x .250 in tubing.
Metric "1/4 in"
Claber groups its tubing into a 4-6 mm (1/4 in) family and a 13-16 mm (1/2 in) family,[9] and labels its 90371 feeding tube 1/4 in, 4-6 mm.[10] That is a different pair of numbers from .170 x .250 in, so the shared "1/4 in" label does not mean shared fit. Our metric drip tubing guide covers joining metric and US parts.
Barbs and stakes
- DIG says both its poly and vinyl 1/4 in microtubing accept 1/4 in barbed fittings.[11] That is DIG's statement about its own tubing.
- Rain Bird lists its TS-025 tubing stake for 1/4 in tubing with a 0.16-0.18 in ID.[12] Tubing outside that ID range is outside the listing.
The sizes at a glance
| Maker and product | Material | ID x OD (in) | Rating the maker lists |
|---|---|---|---|
| Rain Bird XQ | Poly | 0.17 x 0.25 | 0-60 psi |
| DIG micro tubing (2016 catalog) | Poly (LLDPE) | .170 x .250 | Check DIG's current page |
| DIG Microline dripline | Poly | .170 x .250 | See the drip line guides |
| DIG vinyl table | Vinyl | .156 x .245, .160 x .220, .170 x .250 | See the vinyl guide |
| DIG 12-018 (one SKU) | Vinyl | .160 x .270 | See the vinyl guide |
| Mister Landscaper | Vinyl | .145 x .295 | Not stated |
| Claber 90371 | Poly | 4-6 mm | Not stated |
Tubing with stated dimensions
If you are buying new 1/4 in tubing, pick one whose maker states the ID and OD, then match barbs to it. Rain Bird's 1/4 in barbed couplings, elbows and tees push together, can go above or below ground and are rated 0 to 50 psi.[13]
Picks that fit6 products
Choose XQ100 for 100 ft of Rain Bird XQ tubing (0.17 x 0.25 in, 0-60 psi), Raindrip 016010T for 100 ft of Raindrip tubing (0.170 x 0.250 in, no pressure rating stated), T22-50S for 50 ft of Rain Bird blank tubing (0.165 x 0.245 in, plan on 60 psi), DIG B38PB for 50 ft of DIG tubing (.170 x .250 in, up to 60 psi), and BC25/10PS or BC25-30PS (a bag of 10 or 30 Rain Bird 1/4 in barbed couplings, rated 0-50 psi) to join runs.
1/4 in polyethylene tubing with ID and OD stated
1/4 in polyethylene tubing, 100 ft, ID and OD stated
Raindrip 016010T 1/4 in black polyethylene supply tubing (0.170 x 0.250 in, 100 ft)
1/4 in polyethylene blank tubing, 50 ft
Rain Bird T22‑50S 1/4 in blank distribution tubing (0.165 x 0.245 in, 50 ft)
1/4 in polyethylene tubing, ID and OD stated
DIG B38PB 1/4 in polyethylene micro tubing (.170 x .250 in, 50 ft, brown)
1/4 in barbed coupling
1/4 in barbed coupling, bag of 30
On Amazon, check that "Ships from / Sold by" is Amazon.com or the brand before you buy.[14]
Next
Questions
What is the inside diameter of 1/4 inch drip tubing?
Most poly 1/4 in tubing makers list about .17 in: Rain Bird XQ is 0.17 x 0.25 in and DIG lists .170 x .250 in poly. Vinyl sizes vary more, from .145 to .170 in ID in the listings we read.[1][2][8][6]
Is 1/4 inch drip tubing the same size across brands?
No. DIG alone lists vinyl 1/4 in tubing at .156 x .245, .160 x .220 and .170 x .250 in, and Mister Landscaper lists its vinyl at .145 x .295 in.[6][8]
Is 4 mm tubing the same as 1/4 inch?
Not necessarily. Claber labels a 4-6 mm tube as 1/4 in, which is a different pair of numbers from the .170 x .250 in of US poly tubing. Check the actual dimensions before mixing parts.[10]
Do 1/4 inch stakes fit every 1/4 inch tubing?
Rain Bird lists its TS-025 tubing stake for 1/4 in tubing with a 0.16-0.18 in ID, so check your tubing's ID against the stake's stated range.[12]