Hardware purchase
I think it could be either:
'hardware purchase' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Another definition for bolts that I've seen is " Door fasteners".)
(Other definitions for nails that I've seen before include "Talons" , "measure of hardness?" , "they may provide security for the board" , "Horny plates and pointed pins" , "Filed regularly" .)