Window Frame Screw 1)Product : concrete screw 2)Material: C1022, case hardened, surface ... . Window frame screws tap directly into brickwork, doing away with the need for plugs or nylonanchors. They provide ... a wide rang of materials since they are suitable for concrete, solid re brick, hollow, blocks, natural stone, etc ... 182mm, 202mm, 212mm 4) Coating: Zinc, Yellow Zinc Concrete Window Frame Screw