Rationalization proposal Lyubertsy student of secondary school № 42 of Konstantin Shishkin. If you need to turn on a lathe a few identical parts rather complicated configuration, it makes sense to use a universal strap-holder which can be mounted a set of cutters. It is made very simply is a steel bar with a groove in which is invested cutters. In the holder they are fixed by bolt. To change the distance between the incisors allows a set of replacement crackers. The use of this device in a school workshop allowed us to reduce labor costs and increase accuracy of manufacturing of a number of parts.