Brompton Hinge Replacement Thread Tap & Die Set UNF 7/16" -20Brompton Hinge Replacement Thread Tap & Die Set UNF 7 16" 20 The UNF 7 16" 20 tool is specifically used for extracting worn bushes on Brompton bicycles. In Brompton bikes, there are various components such as the suspension block and other parts that incorporate bushings. Over time, these bushings can wear out due to regular use and exposure to various elements. When these bushings become worn, they can affect the smooth operation of the bike's