Countersunk irangiza ishusho ni ibyiciro byihariye byagenewe kwakira umutwe wa screw cyangwa bolt, kwemerera kuri flush irangiye. Iyi moshi iratandukanye kubera imiterere ya conical, ifasha gufata kwicara munsi yubuso bwibikoresho, gukora isura yoroshye kandi nziza ishimishije. Igishushanyo gifite akamaro cyane mubikorwa aho sleek na pro.