Hose size
4 in dust collector hose and fittings: what 4 in really measures
Four makers' 4 in parts measure differently: POWERTEC's 70136, 70291, 70147 and 70135. Collector inlets, couplings and gates, and the PVC sizes to avoid.
Also listed as 4 inch dust hose, 4 in hose, 100 mm class hose
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Short answer
4 in is the common collector inlet, hose and fitting label, but each maker's 4 in part measures differently: POWERTEC's 70136 end is 3-61/64 in OD, its 70291 tapers from 3.51 to 3.73 in to go inside a 4 in nominal OD port, and its 70135 gate tapers from 3-29/32 to 3-31/32 in. The catch: a 4 in hose fitting, 4 in S&D pipe and 4 in Schedule 40 pipe are three different parts. See choosing 4 in collector hose.
What fitsAll 6 items that fit
- 4 in hosePOWERTEC 70111 4 in x 10 ft clear flexible PVC dust collection hose, left-hand spiralCheck price on Amazon
- Left-hand bridge clampsPOWERTEC 70226 4 in keyed left-hand bridge hose clamp, 5‑packCheck price on Amazon
- Key clampsPOWERTEC 70260 4 in keyed bridge hose clamp, 10‑packCheck price on Amazon
Key facts
- What the label measures
- Each maker's part differs: POWERTEC 70136 4 in end 3-61/64 in OD, 3-41/64 in ID; 70291 tapers 3.51 to 3.73 in to fit inside a 4 in nominal OD port; 70147 3.965 in OD; 70135 gate outlet tapers 3-29/32 to 3-31/32 in[3][4][5][6]
- Maker-dimensioned examples
- Collector inlets: [Grizzly G8027](/vacuums-and-collectors/grizzly-g8027) 4 in intake and main inlet; [Central Machinery 59726](/vacuums-and-collectors/central-machinery-59726) 4 in inlet[1][7][2]Both are nominal values with no stated mating diameter.
- Tank and cuff ends
- Infinity 115-313 gate: tapered fittings on both sides to accept 4 in hose, hose clamps required[8]Infinity does not state the end OD or ID.
- Metric arithmetic
- 4 in x 25.4 = 101.6 mm[9]Arithmetic, not a fit allowance.
- Step adapters to other sizes
- POWERTEC 70136 (4 in to 2-1/2 in, hoses only), 70291 (into a 4 in nominal OD port), 70147 (4 in to 2-1/4 in)[3][4][5]
- Couplers and clamps
- Magport 4 in magnetic coupling (sold singly, needs more than one unit; collar 4 in OD for 4 in flex hose). MagFitt 4 in machine coupling (works with MagFitt's own connectors). Infinity MagSnap in 4 in and 2-1/2 in, each port with a hose clamp[10][11][12]No maker states cross-brand magnetic fit.
- Separators made for this size
- Oneida Super Dust Deputy 4/5: 4 in reducer adapters for inlet and outlet. Shop Fox W1049 lid: molded inlets and outlets for 4 in flexible hose[13][14]
- Do not confuse with
- 4 in [S&D PVC](/fitting-standards/sewer-and-drain-pvc) (WoodRiver's adapter fits inside S&D with a 4.065 in ID) and 4 in [Schedule 40 PVC](/fitting-standards/schedule-40-pvc) (Rockler 52680's rubber end is 4.5 in ID)[15][16]
- Not confirmed
- Not confirmed
Watch out for
- POWERTEC's 70136 fits hoses only; its 70291 goes inside a 4 in nominal OD machine port. The same '4 in' label covers both jobs.
- MagFitt's page says nothing about Magport, and no maker states cross-brand magnetic fit.
- POWERTEC's 70135 page also carries a broad size claim that conflicts with its single 4 in size; go by the dimensioned taper.
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 hose
POWERTEC 70111 4 in x 10 ft clear flexible PVC dust collection hose, left-hand spiralChoose the 4 in x 10 ft hose.
POWERTEC sells it for 4 in dust collection systems, left-hand spiral.
Left-hand bridge clamps
POWERTEC 70226 4 in keyed left-hand bridge hose clamp, 5‑packChoose the 5-pack of left-hand clamps.
POWERTEC lists them for left-hand spiral 4 in hose with a 3-3/4 to 4-3/8 in range. A bridge clamp fits only hose of its own spiral hand.
Key clamps
POWERTEC 70260 4 in keyed bridge hose clamp, 10‑packChoose the 10-pack of 4 in key clamps.
POWERTEC lists a 3-1/2 to 4-3/8 in clamping range.
Wye
POWERTEC 70106 4 in Y-fitting dust hose connectorChoose the single 70106 4 in Y-fitting.
POWERTEC lists three 4 in ports of 3-61/64 in OD and 3-3/4 in ID, sized to go inside 4 in ID hose.
Blast gate
POWERTEC 70135 4 in aluminum blast gateChoose the 2-pack of 70135 gates.
POWERTEC lists a nominal 4 in OD outlet tapering from 3-29/32 to 3-31/32 in.
Reducer
POWERTEC 70136 4 in to 2‑1/2 in cone reducerChoose the single 70136 cone reducer.
For 4 in hose to 2-1/2 in hose only; POWERTEC says it is not made to fit machine ports.
Questions
Is every 4 in dust fitting the same size?
No. POWERTEC alone lists its 4 in ends at 3-61/64 in OD (70136), 3.965 in OD (70147), a 3.51 to 3.73 in taper (70291) and a 3-29/32 to 3-31/32 in taper (70135).[3][5][4][6]
Does a Magport coupling work with MagFitt parts?
Not confirmed. Woodcraft lists the MagFitt coupling as working with MagFitt's own connectors and says nothing about Magport. See magnetic dust fittings.[11]
Can I push 4 in hose fittings into 4 in PVC pipe?
Rockler says S&D pipe does not connect directly to most dust fittings without an adapter, and its Schedule 40 adapter has a 4.5 in ID rubber end. See S&D vs Schedule 40.[17][16]