Home - Twinco Mfg. Co., Inc. manufacturing, machine shop, machine shops, custom manufacturing, railroad and transit products, rail and transit products, identification products, ID Products, custom manufacturing, contract manufacturing, AAR hardware, terminal blocks, washers, binding nuts, insulated nuts, wayside equipment, automatic train stops, vital relays, impedance bonds, engraved nameplates, wire markers, metal tags, relay contacts, rectifiers Twinco is a leading supplier and producer of electrical and electro-mechanical products for the railroad and transit industry. We have over 50 years of experience in the …