Blue Anodized Aluminum Adapter (AN 932), Inch Male NPT Allen Head Plug

For capping off an inch male NPT port, this is the right style of part. It is an AN 932 male NPT Allen head pipe plug, so it threads in and seals like a typical NPT plug, and the internal Allen drive makes it easier to install and back out later compared to a square head.

According to Eaton Aeroquip, this adapter is compatible with a wide range of hydraulic fluids, so you should be covered for most common industrial applications. For specifics, check out the fluid compatibility document link.

Aluminum works fine for capping hydraulic ports, and the anodized finish on this one adds a solid layer of corrosion protection that holds up well in industrial environments. The Eaton Aeroquip build quality is consistent, so you're not getting a soft or flimsy plug. As long as the port is inch male NPT, this fits the bill for manifolds, blocks, or any system where you need a clean, leak-free seal on an unused port.