Black 304 Stainless Steel 12" Piano Hinges (2-Pack)

I used these piano hinges to build the hidden cabinet in the corner of my lower engine-area cabinets. The continuous hinge supports the door along its length and lets the panel swing open while keeping the hardware low-profile.
 
They worked perfectly for turning an otherwise awkward corner into hidden, usable storage without having a bulky traditional hinge setup visible from the outside.