Single-layer steel common
That means a lot of single-layer steel doors, some older wood panel doors on wide two-car openings, and torsion or extension spring setups that were standard for that build era rather than anything custom. We carry torsion springs sized for those older 16-foot doubles, extension spring pairs for the narrower singles, and steel rollers and hinges that match the hardware gauge from that period - not the lighter stamped stuff sold today.
