2PCS Quick Plug Set (Japanese, female thread)

A plug is the tool-side half of a quick-connect air system: it stays screwed into the tool, and it pushes into the coupler on the hose. Which thread you need depends on how the tool's air inlet is made. Some tools have a female threaded port, and take a male-threaded plug. Others have a male threaded stub, and take a female-threaded plug like these. Both arrangements are common, neither is more correct, and ordering the wrong one is the most frequent mistake made with air fittings.

So before ordering, look at the air inlet on the tool itself. If it is a hole with a thread inside, you want the male-thread set (683701). If it is a projecting threaded stub, you want this one.

"Japanese type" describes the coupler profile, not where it was made. Japanese, European and American profiles look similar enough to be confused and do not properly fit one another — a mismatched pair hisses continuously, restricts flow, and sometimes will not release under pressure. The entire Harden air range here is Japanese type, so the hose, the couplers and these plugs all mate correctly with each other.

Rated to 220psi, well above what a normal workshop compressor delivers.

One piece of fitting advice that saves a lot of irritation: use PTFE tape on the thread. When a quick-connect joint hisses, it is nearly always the screwed thread leaking rather than the push-fit connection, and a small permanent leak means the compressor cycles all day and wears itself out for nothing.

The buyers are vehicle workshops, tyre and exhaust shops, machine and fabrication shops, air-conditioning engineers, and anyone extending a compressed air installation. They come two to a pack because plugs are fitted per tool and get damaged in use.

We stock the matching 5 and 6-piece coupler sets and the 10m PU hose. Message us on WhatsApp and tell us what the tool's inlet looks like — we will make sure you get the right gender, delivered island-wide.