A double-square screw head is usually employed on industrial-stage types together with haulmark trailers. These screwdrivers attribute a blunt idea, with tiny ribs alongside the blade concerning the main edges. The look allows to boost torque and reduce the chance of the driver camming out for the duration of operation. https://typesofmetalceiling48264.livebloggs.com/35570484/types-of-screw-heads-for-screwdrivers-fundamentals-explained