Set screws, yomwe imadziwikanso kuti grub screws, ndi mtundu wa zomangira zomwe zimagwiritsidwa ntchito kuteteza chinthu chimodzi mkati kapena motsutsana ndi china. Mosiyana ndi ma bolts ndi zomangira zachikhalidwe, zomangira sizikhala ndi mutu ndipo nthawi zambiri zimakhala ndi ulusi. Amapangidwa kuti azithamangitsidwa mu dzenje lobowoledwa kale ndipo nthawi zambiri amakhala ndi mfundo kapena kapu kumapeto komwe kumatha kukanikiza pa shaft kapena chigawo china, kupereka zolimba, zotetezeka. Mu positi iyi yabulogu, tiwona mbali zazikuluzikulu za zomangira, kuphatikiza mitundu yawo, zabwino zake, ndi kugwiritsa ntchito wamba.