We manufacture and stock a complete line of model hex cap screws, washers and nuts in brass and steel from 0-80 x 1/8" to 10-32 x 2".  We also supply the same screws and nuts in stainless steel from 2-56 x 1/8 to 10-32 x 1".  The form of these bolts and nuts is based on the American Standard and Unified Standard Heavy Hex standards.  This was the standard used by most of the machinery makers at the end of the 19th and early 20th century.