Brake unions are standard 7/16" UNF 20Tpi thread. CLASSIC CAR BRAKE PIPE UNIONS x5. If you are not 100% happy with the part you ordered, we will replace the part or your money back. vehicles like; Austin, Ford, Jaguar, MG, Triumph, Morris, Mini, Vauxhall, Wolseley, Oxford, Cowley and often used in kit cars.