A plastic casement windows operator has a plastic housing, a plastic sliding tounge and a plastic operating lever. The housing has a plastic main body and a plastic cover with complementary peripheral steps and peripheral energy directors and inward extending receivers and pins with energy directors for joining the cover and main body after the plastic sliding tounge and plastic operating lever are installed. The main body has an inward extending cylindrical bearing opening, which holds a cylindrical bearing integrally formed between an operating handle and an activator arm. An activator cylinder at a remote end of the arm moves in an oval groove in the sliding tounge. Wings on the tounge support opposite jugs and cylindrical guides which slide along inner guides on the cover and main body. An extension on the flat body tounge has a U-shaped opening for connecting a window linkage. Integral rims extend around the tounge, the U-shaped opening and the oval groove.