Shortlist · Wyes, elbows and reducers
Reducers and adapters with both ends dimensioned
Three POWERTEC dust fittings with both ends dimensioned: the 70136 4 to 2-1/2 in cone reducer, the 70147 4 to 2-1/4 in adapter and the 70189 6 x 4 x 4 in Y.
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Short answer
To step 4 in hose down to 2-1/2 in hose, POWERTEC's 70136 cone reducer dimensions both ends and says it is for hoses only.[1] To reach a part that takes a 2-1/4 in male end, the 70147 states both outside diameters.[2] To split a 6 in end into two 4 in lines, POWERTEC's 70189 Y dimensions all three ends.
How we chose
A fitting is on this list only if:
- Its maker dimensions both ends. POWERTEC lists the 70136 at 3-61/64 inches OD and 3-41/64 inches ID on the 4-inch end[1] and 2-15/32 inches OD and 2-9/32 inches ID on the 2-1/2-inch end.[1]
- Its maker says where each end goes. POWERTEC says the 70136 fits hoses only and is not meant for equipment ports.[1] Its 70291, by contrast, friction-fits inside a 4-inch nominal OD machine port[3] and fits inside most 2-1/2-inch ID collector hoses.[3] Same family name, different jobs.
- Marketing stays out. POWERTEC's airflow claims for the 70147 have no published data,[2] so we do not repeat them.
- The product is an exact brand and model in our catalog, and its store listing shows a button only after a US "Ships from / Sold by" check.
Three approved fittings met this bar on 2026-10-14. The 70291 is not in our catalog yet.
4 in hose to 2-1/2 in hose
POWERTEC 70136 4 in to 2‑1/2 in cone reducer
Pick it if: Stepping a 4 in hose down to a 2-1/2 in hose
- Why it's here
- POWERTEC lists the 70136 at 3-61/64 in OD and 3-41/64 in ID on the 4-inch end and 2-15/32 in OD and 2-9/32 in ID on the 2-1/2-inch end, in heavy-walled ABS.
- Watch out
- POWERTEC says it fits hoses only and is not intended to fit a 2-1/2-inch OD or 4-inch OD equipment port directly. On Amazon, check that 'Ships from / Sold by' shows Amazon.com or POWERTEC.
- Nominal size family
- 4 in to 2-1/2 in
- Inside and outside diameter of each end
- 4 in end 3-61/64 in OD, 3-41/64 in ID; 2-1/2 in end 2-15/32 in OD, 2-9/32 in ID
- End type (male or female)
- Both ends male, made to go into hoses only; not for direct fit to 4 in OD or 2-1/2 in OD equipment ports
- Fitting standard (hose fitting, S&D PVC, Schedule 40, metal pipe)
- Hose fitting
Values are the manufacturer's specs unless marked.
4 in hose to a 2-1/4 in port or hose
POWERTEC 70147 4 in to 2‑1/4 in tapered adapter
Pick it if: Joining 4 in collector hose to a part that takes a 2-1/4 in male end
- Why it's here
- POWERTEC lists the 70147 with a 3.965-inch OD on the 4-inch end and a 2.26-inch OD on the 2-1/4-inch end, in non-threaded black ABS.
- Watch out
- POWERTEC gives no inside diameters. Its airflow and velocity claims for this part have no published data, so we do not repeat them. On Amazon, check that 'Ships from / Sold by' shows Amazon.com or POWERTEC.
- Nominal size family
- 4 in to 2-1/4 in
- Inside and outside diameter of each end
- 4 in end 3.965 in OD; 2-1/4 in end 2.26 in OD
- End type (male or female)
- 4 in end press-fits into 4 in hose; 2-1/4 in end inserts into a 2-1/4 in ID tool or shop-vac port
- Fitting standard (hose fitting, S&D PVC, Schedule 40, metal pipe)
- Hose fitting (non-threaded)
Values are the manufacturer's specs unless marked.
6 in end split to two 4 in lines
POWERTEC 70189 6 x 4 x 4 in Y-fitting
Pick it if: A 6 in collector inlet or main that has to feed two 4 in hoses
- Why it's here
- POWERTEC lists the 70189 wye with a 6 in end of 6-23/64 in OD and 6 in ID and two 4 in branches of 3-61/64 in OD and 3-23/32 in ID, in black ABS.
- Watch out
- A 6 in inlet varies by machine and version, so confirm yours first; Grizzly's W1685 parts list shows a 6 x 4 x 4 inlet Y for one version and a 5 x 4 x 4 for an earlier one. On Amazon, check that 'Ships from / Sold by' shows Amazon.com or POWERTEC.
- Nominal size family
- 6 in to two 4 in
- Inside and outside diameter of each end
- 6 in end 6-23/64 in OD, 6 in ID; each 4 in branch 3-61/64 in OD, 3-23/32 in ID
- End type (male or female)
- Not stated
- Fitting standard (hose fitting, S&D PVC, Schedule 40, metal pipe)
- Not stated
Values are the manufacturer's specs unless marked.
Fit table
| Pick | Large end | Small end | Goes into |
|---|---|---|---|
| POWERTEC 70136 | 3-61/64 in OD, 3-41/64 in ID | 2-15/32 in OD, 2-9/32 in ID | Hoses only |
| POWERTEC 70147 | 3.965 in OD | 2.26 in OD | Hose or a part that takes a male end |
| POWERTEC 70189 Y | 6-23/64 in OD, 6 in ID | Two 3-61/64 in OD branches | Hoses |
Where standards meet
These are hose fittings. A PVC run needs an adapter made for its pipe. Rockler lists a Schedule 40 to 4-inch fitting adapter (52680) with a 4.5-inch ID rubber end and a 3.99-inch OD plastic end.[4] Woodcraft says its WoodRiver S&D adapter fits inside 4-inch S&D pipe with a 4.065-inch ID and works only with left-hand threaded hose.[5]
Next
Questions
Which reducer goes straight into a 4 in machine port?
Not the 70136, which POWERTEC says fits hoses only. POWERTEC's 70291, which is not in our catalog, has a 4-inch end that tapers from 3.51 to 3.73 inches and friction-fits inside a 4-inch nominal OD machine port.[1][3]
Do these fit PVC pipe?
No. They are hose fittings. Pipe needs an adapter made for its standard, such as Rockler's Schedule 40 to 4-inch fitting adapter or Woodcraft's WoodRiver S&D adapter.[4][5]
Why do the 4 in ends measure less than 4 in?
Because they are made to go inside 4 in hose. The label is the family; POWERTEC's 70136 4-inch end is 3-61/64 inches OD.[1]