The Rack Rails support flange is 23 1/2" long. The Rack Rail will support servers computers or equipment up to 35" deep. The 1U Rack Rails Minimum Equipment Width is 16 5/8". Rack Rails standard thumb screw threads (10-32, 12-24, and metric M6). The 1U Rack Rail is made of 0.049" steel with a durable zinc plating.