1-1/4 in. (31.75mm) Dust Port Tools and Vacuum Adapter Guide for DeWalt, Milwaukee, and Porter-Cable
A 1-1/4 in. (31.75mm) port is the most common cordless hand-tool standard in the US. The port is round, about 31.75mm across on the inside and about 35mm on the outside. Many DeWalt 20V MAX and FlexVolt 60V tools use it, so do a handful of Milwaukee M18 saws and a Porter-Cable sander.
If you do not own a DeWalt or Milwaukee branded vac, your shop vac hose is the wrong size. A 1-7/8 in. or 2-1/2 in. hose end is much larger than 31.75mm. A sized PETG adapter bridges the gap so the tool pulls dust into the vac instead of past it.
Below is every tool with a verified 31.75mm dust port that we track. Each link goes to that tool's full page with the exact size, the source we cite, and the adapter that fits.
Every 1-1/4 in. Dust Port Tool
Tools that use the 1-1/4 in. port. Click any tool for its full specs and the exact adapter that fits it.
DeWalt3 tools
The Adapter That Fits a 1-1/4 in. Port
Each adapter grips the 1-1/4 in. tool port on one end and steps it to your shop vac or dust extractor hose on the other end. Friction fit, no clamps. Made in the USA.
What 1-1/4 in. (31.75mm) Means on a Tool Port
A 1-1/4 in. port measures about 31.75mm across on the inside. On the outside it usually runs about 35mm. The port is round and uses a friction fit, so a sized adapter pushes on and stays put.
The DCW600B router verifies a touch under at 31.2mm inside; the Milwaukee 2732-20 circular saw and the DCS520T1 track saw both verify at the full 31.75mm inside. The 0.55mm gap between 31.2 and 31.75 falls inside the PETG friction-fit clearance, so one adapter snugs into both.
Most US shop vac hoses are 1-7/8 in. or 2-1/2 in., both much wider than 1-1/4 in. That gap is why a hose laid against the tool port leaks dust into the air instead of into the vac.
How to Confirm Your Tool Is 1-1/4 in. Before You Buy
Open the tool detail page on this site for your specific model. If we have a verified port size on file, the page shows the exact mm and a link to the source we cite. If the port is provisional, the page shows a 'measure to confirm' banner.
If your model is not in the list above, measure the port with calipers. Close the jaws around the OUTSIDE of the port stub. That is your outer diameter. The inside diameter is your stub-fit target. Round to the nearest standard size if your number falls between two.
Why the Same Adapter Fits These Different Tools
Every tool listed above has a round 31.75mm interior port (the DCW600B is a touch under at 31.2mm). The adapter sized for 31.75mm has the friction clearance to seat in all four.
Outside of the verified four, do not assume the 1-1/4 in. label on a different cordless tool means it is exactly 31.75mm. The Milwaukee 2723-20 router shipped 'M18' branded but verifies tapered (about 30mm at the grip to 34.6mm at the lip). That is a different geometry, and a straight cylinder will not seat. Use the tool detail page for the tool you own.
1-1/4 in. Dust Port FAQ
Which power tools really use the 1-1/4 in. (31.75mm) port?+
Four tools have a verified 1-1/4 in. dust port that we ship an adapter for: the DeWalt DCW600B router (verifies 31.2 inside), the Milwaukee 2732-20 M18 FUEL 7-1/4 in. circular saw, the DeWalt DCS520T1 FlexVolt 60V track saw, and the Porter-Cable PCC761B random orbit sander. Many other cordless tools default to about this size on the package, but the per-tool detail page is the truth.
Why is the DCW600B listed at 31.2mm if the hub is 31.75mm?+
The DeWalt OEM DNP615 adapter verifies the DCW600B port at 31.2mm inside and 38.6mm outside. The 0.55mm gap to a 31.75mm adapter sits inside the PETG friction-fit clearance, so the same adapter seats on both. We list the DCW600B here because it shares the same adapter, not because the port measures exactly 31.75mm.
Does the Milwaukee 2723-20 router belong on this hub?+
No. The 2723-20 verifies as a tapered port, about 30mm at the grip and about 34.6mm at the lip. A straight 31.75mm adapter will not seat correctly. Use the 2723-20 tool detail page for the tapered adapter that fits it.
Can I use a regular shop vac with these tools?+
Yes, with the right adapter. A 1-7/8 in. or 2-1/2 in. shop vac hose is much wider than 31.75mm. The GulpDust PETG adapter fits the 1-1/4 in. tool port on one end and your shop vac hose on the other.
Can I print this adapter myself?+
Yes. You can buy the printed PETG part shipped from the US, or download the STL and print it at home. We suggest PETG with 3 walls and 25 percent infill.