If you need to step down in the DC system, which is recommended, this works great. The ends are to size stated, the hose fit easily and the wire clamps put it all together snuggly. The fitting allows you to step down from a larger main line to smaller branch lines near the machine, thus increasing the air suction, where it’s needed most, by the machine.
– Is this really what you need?
I bought this to connect my 4″ Jet hose to the 2 1/2 port on my bandsaw and table saw. All the current research is to keep the dust collector draw (I have the Jet 1100) at 4″ (6″ on a planer) until right before the machine (actually to rebuild any machine to accept a 4″). The ad does say it’s 2 1/2 OD and silly me, I didn’t bother measuring the 2 1/2 at the tool end. Guess what? They’re both 2 1/2 OD so they do NOT fit together. In my opinion, this is a worthless adapter – as it doesn’t advertise as a hose to hose connector, and hooking a 2 1/2 shop vac to a 4″ opening at the tool is like trying to suck dust out of a garbage can with a straw – the physics are wrong – this should be only used for reducing a 4″ hose to 2 1/2″ at the tool, but again it’s the wrong diameter. A proper adapter should be either 2 1/4 OD or 2 1/2 ID to fit over the tool’s port. Does anyone know where to find such an animal? I finally found a rubber plumbing connector (at Home Depot) that joined the two 2 1/2 OD fittings together. This works but we should’ve have to do this for a peice of plastic they charge over $5 for. Please do not hook a shop vac to a jointer and expect to remove the 1 to 5 micron diameter dust particles that can cause COPD (lung disease), you’ll only get the chips, sort of.
– The two most popular sizes can now talk to one another
This adapter is great for mating the popular 2 1/2″ vacuum hose size to your 4″ hoses. This 4″ is a male end that will fit well into your 4″ hose acting as a female, and the 2 1/2″ end is a female that will receive your 2 1/2″ hose as a male. 🙂 I don’t know why that is so funny, but it strkes me that way. That is the best description I can give it. These Jet adapters fit perfectly. To securely connect this adapter, I suggest that you buy the Jet wire connectors, instead of the standard band clamps. Since most dust collection hoses have a wire running through them, band clamps can not compress them. The Jet wire clamp goes around the wire in the hose, and it grips the material directly to the fitting. I tried using the band clamps, and after having to reattach them on a regular basis, I went to the Jet 4″ wire clamps, that is why I am making such a big deal out of it. I have never had to retighten, or reinstall the hose on the adapter since. The wire clamps work perfectly. Highly recommended.