Where's molly?

[Laurence Horn]

A standard term for a plastic bolt used to mount something in dry
wall is "molly".  If you go into any hardware store and ask for some
mollies or molly bolts, you will be understood.  Yet neither the ADH4
nor the OED (on-line version) contains this lexical item.  What
happened?

larry

P.S.  I have no idea what the derivation of this word is, and I
suppose it's conceivable that it derives from a proper name and/or
brand name, but as a web search (under "molly bolts") indicates, it
certainly is treated as a common noun in solo appearances and
compounds.