Thank you very much, Patxi!
I'll check out Coop again, armed with the proper word. Keder Werkzeug - who'd a thunk it?
(You've saved my screen door, and probably my marriage.
Pity the poor clerks we buttonholed while foraging for the thingamabob; OH speaks fluent DIY, but little German. I speak German but am a DIY ignoramus. They must have thought we were both off our rockers as we tried - and failed - to describe what we needed.)