Silindernurgik on metallitöötluses kasutatav raske terasest silinder, mis on töödeldud suure täpsusega ja mille otsad on silindri teljega risti ning asetades selle püsti teadaolevale tasasele pinnale, nt tasaplaadile, saab seda kasutada teiste esemete sh ka töönurgikute täpsuse kontrollimiseks.
A cylinder square is a heavy solid steel cylinder used in metalworking that has been machined to a high degree of accuracy, with the ends perpendicular to the axis of the cylinder, and by placing it upright on a known flat surface, such as a surface plate it can be used for checking the accuracy of other items, such as engineer's squares.
