Hose size
2-1/4 in shop-vac tank ends and fittings: what the size measures
2-1/4 in usually names a tank end's outside diameter, not a hose bore. Cen-Tec, Bosch and POWERTEC examples, and the 2-1/2 in mix-up to avoid.
Also listed as 2.25 in, 2-1/4 inch
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Short answer
2-1/4 in usually names the outside of a tank end, not a hose's bore: Cen-Tec's 42324 cuff ends in a 2.25 in OD press fit, Bosch's VAC005 vacuum end is a standard 2-1/4 in friction fit, and POWERTEC's 70147 lists its 2-1/4 in end at 2.26 in OD. The catch: 2-1/4 and 2-1/2 in get mixed up, even on a maker's page. See nominal vs actual hose sizes.
What fits
- 4 in to 2-1/4 in adapterPOWERTEC 70147 4 in to 2‑1/4 in tapered adapterCheck price on Amazon
- Threaded couplerPOWERTEC 70408 threaded coupler adapter, 2‑1/2 to 2‑1/4 in taper to 1‑1/2 in ID hoseCheck price on Amazon
- 35 mm hose with 2-1/4 in endBosch VAC005 35 mm x 16.4 ft friction-fit vacuum hoseCheck price on Amazon
Key facts
- What the label measures
- Usually a tank end's outside diameter: Cen-Tec 42324 has a 2.25 in OD press fit; Bosch's VAC005 vacuum end is a standard 2-1/4 in friction fit[1][2]
- Maker-dimensioned examples
- POWERTEC 70147: 2-1/4 in end at 2.26 in OD[3]POWERTEC gives no ID for either end.
- Tank and cuff ends
- Cen-Tec 42324 cuff: 1.25 in threaded hose end to a 2.25 in OD tank connector. Bosch VAC005: 35 mm hose to a 2-1/4 in friction-fit vacuum end, for wet-dry vacs with a 2-1/4 in friction-fit port[1][2]Cen-Tec does not state fit to any specific tank.
- Metric arithmetic
- 2.25 in x 25.4 = 57.15 mm[4]Arithmetic, not a fit allowance.
- Step adapters to other sizes
- POWERTEC 70147: 4 in to 2-1/4 in tapered adapter, 3.965 in OD to 2.26 in OD, non-threaded ABS[3]
- Couplers and clamps
- Not confirmed
- Separators made for this size
- Not confirmed
- Do not confuse with
- 2-1/2 in: DEWALT Canada lists the DWV9190 for a '2 1/2' hose OD similar to RIDGID or Shop-Vac, but the same page shows '57.2 mm', which is 2-1/4 in[5]The page conflicts with itself, so no DWV9190 dimension is published here.
- Not confirmed
- Not confirmed
Watch out for
- 2-1/4 in is usually a male tank end's outside diameter, so a 2-1/4 in part goes into the vacuum, not over it.
- DEWALT Canada's DWV9190 page says 2-1/2 in and 57.2 mm (2-1/4 in) for the same part, so even maker pages blur the two sizes.
- POWERTEC's 70147 airflow wording has no data behind it; treat it as a maker claim, not a reason to choose the part.
What fits
Product details below are the seller's own description unless a source is shown. Pick the variant named for each item.
4 in to 2-1/4 in adapter
POWERTEC 70147 4 in to 2‑1/4 in tapered adapterChoose the 70147 4 in to 2-1/4 in adapter.
POWERTEC lists 3.965 in OD on the 4 in end and 2.26 in OD on the 2-1/4 in end, and sells it for shop vacuums with a 2-1/4 in ID port.
Threaded coupler
POWERTEC 70408 threaded coupler adapter, 2‑1/2 to 2‑1/4 in taper to 1‑1/2 in ID hoseChoose the 70408 threaded coupler.
POWERTEC says it fits nominal 2-1/4 in ID shop-vac ports and threads onto 1-1/2 in ID hose with left-hand threads.
35 mm hose with 2-1/4 in end
Bosch VAC005 35 mm x 16.4 ft friction-fit vacuum hoseChoose the VAC005 35 mm x 5 m hose.
Bosch says the vacuum end is a standard 2-1/4 in friction fit for wet-dry vacs with a 2-1/4 in friction-fit port.
Questions
Is a 2-1/4 in tank port the same as a 2-1/2 in hose?
No. They are different labels, and even DEWALT Canada's DWV9190 page shows both '2 1/2' and 57.2 mm (2-1/4 in) for one part. Check what each end measures.[5]
What does 2-1/4 in measure on a tank cuff?
On Cen-Tec's 42324 it is the outside diameter of the press-fit tank connector (2.25 in OD).[1]
How do I step a 4 in collector hose down to a 2-1/4 in port?
POWERTEC lists its 70147 adapter at 3.965 in OD on the 4 in end and 2.26 in OD on the 2-1/4 in end. The reducer guide covers which end goes where.[3]