Soss invisible hinge model #101 is for use in wood or metal applications. This cabinet style hinge will provide superior appearance and durability. Our Hinges are found in many applications where flush fit, compact size and smooth operation are necessary features. Soss invisible hinges open a full 180 degree and are a single action hinge. Wood Screw Size: #5 x 3/4". Soft Wood Pilot Hole: No. 53. Hard Wood Pilot Hole: No. 47. Machine Screw Sizes: #4-40 x 1/2".