Why do they even use buttress threads on drums and what can I do about it?

In the early days of drums, it was challenging to mold fine pipe threads directly into the drum precisely. The fine threaded plugs would cross thread, strip out or leak when you tightened them. The solution to this was the heavy, strong buttress thread. Plastic drum technology is vastly improved, and NPS plugs perform just as well as buttress plugs. However, most drums still include a buttress thread.

Plastic drums often have two bungs; a 2" NPT opening and a coarse 2" buttress thread opening. The problem is that the "buttress" thread doesn't fit many standard faucets or pumps.

The solution to this is the 180132 2" Buttress x 2" NPT Drum Adaptor. This adapter will thread into the buttress thread on your drum and adapt to a 2" female NPT thread that you can use to connect standard pumps, faucets, and vents.

Don't know what thread you have on your drums? Here is how you tell the difference between buttress and NPT threads.

A way to distinguish between NPT and Buttress is by their appearance. Buttress threads have a thread where the lines are spaced further apart, making them look more coarse. So they are sometimes called "coarse threads." NPT, by contrast, has threads much closer together, so they are often referred to as "fine threads."