Connect a Bosch 27 mm tool port to a 1-1/4 in shop-vac hose
How to join a Bosch 27 mm tool port to a 1-1/4 in shop-vac hose, and what stops it leaking dust.
Not a direct fit. Joining the Bosch 27 mm tool port to a 1-1/4 in shop-vac hose needs a 27 mm to 1-1/4 in step reducer.
Rings drawn to scale from the measured diameters in the table below.
The two ends
| End A | Bosch 27 mm tool port (1-1/16 in OD, 27 mm OD) |
|---|---|
| End B | 1-1/4 in shop-vac hose (approx 1-1/2 cuff in OD, 1-1/4 in ID) |
| Fit type | male port into hose cuff |
| Reducer needed | 27 mm to 1-1/4 in step reducer |
Shop notes
Measured across the joint between the Bosch 27 mm tool port and the 1-1/4 in shop-vac hose, the hose (32 mm) is 5 mm larger than the port (27 mm), so the port rattles inside without gripping. A 27 mm to 1-1/4 in step reducer closes that 5 mm step so the two hold together instead of leaking at the gap.
A 5 mm mismatch feels close enough to force, and it will hold for a minute before it works loose under airflow. Fit the step ring rather than trusting friction on a gap this size.
The reducer to buy
Search Amazon for 27 mm to 1-1/4 in step reduceraffiliate searchRelated connections
- Bosch 27 mm tool port27 mm OD
- 1-1/4 in shop-vac hose1-1/4 in (approx 32 mm)
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