TYPES OF SCREW HEADS FOR DUMMIES

such a screw head looks like the Phillips, apart from that it's a couple of a lot more grooves that make it show up star-shaped. A triple-sq. screw is also called XZN. This screw is built by overlaying three symmetrical squares to sort twelve uniformly spaced details which are ninety levels. just like the Philips screw head in that it's click her