PortMatch
CONNECTION

Connect a DeWalt DWE7491RS blade-guard port to a 1-7/8 in shop-vac hose

How to join a DeWalt DWE7491RS blade-guard port to a 1-7/8 in shop-vac hose, and what stops it leaking dust.

Reducer required

Not a direct fit. Joining the DeWalt DWE7491RS blade-guard port to a 1-7/8 in shop-vac hose needs a 1-1/2 in to 1-7/8 in step reducer.

END B47.6 mm1-7/8 in shop-vac hose (1-7/8 in ID)
END A38 mmDeWalt DWE7491RS blade-guard port (1-1/2 in OD, 38 mm OD)

Rings drawn to scale from the measured diameters in the table below.

The two ends

End ADeWalt DWE7491RS blade-guard port (1-1/2 in OD, 38 mm OD)
End B1-7/8 in shop-vac hose (1-7/8 in ID)
Fit typemale port into hose cuff
Reducer needed1-1/2 in to 1-7/8 in step reducer

Shop notes

Measured across the joint between the DeWalt DWE7491RS blade-guard port and the 1-7/8 in shop-vac hose, the hose (48 mm) is 10 mm larger than the port (38 mm), so the port rattles inside without gripping. A 1-1/2 in to 1-7/8 in step reducer closes that 10 mm step so the two hold together instead of leaking at the gap.

A 10 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.