Hobson IMPAX Square magnetic power driver bitare also known as Robertson bits were invented in 1908 by P.L Roberston a Canadian. The head has a slight taper which makes inserting the bit and keeping the screw on the bit a great deal easier. There are a lot more reliable than phillips and slotted bits if you are trying to avoid cam-out. They are available in sizes SQ1 SQ2 and SQ3. Specifically developed for use with the high-torque output of an impact driver Power bits have a 1/4" hex shank with power groove for use in modern impact drivers drill drivers and quick change adapters What is the difference between an insert bit and a power bit? Insert bits are commonly used with a magnetic bit holder in a drill driver power tool. This combination is economical provides flexibility and allows a fastener to be magnetically held by the bit but the range is limited to lengths of upto 50mm. Power bits are placed directly into the 1/4" quick-change hex shank or drill chuck no other parts are required and are available in lengths upto 300mm long What is the difference between drill driver and impact driver? A standard drill-driver is an excellent all-purpose tool. The head includes a chuck used to hold bits in place. Both standard screwdriver bits and drill bits can be used which enhances its versatility. The tool generally has a low speed used for driving screws and other fasteners and a higher speed for drilling. Standard power drills also include a clutch allowing you to adjust the level of torque. This is important to prevent fasteners from being over tightened and to prevent the drill from damaging the materials. By contrast an impact driver is more compact and lightweight than a standard drill-driver and usually has more torque or twisting force. Generally cordless impact drivers are either 12-volt 18-volt or 20-volt MAX models. All material is advisory only and its use by anyone is entirely voluntary. Reliance on it for any purpose by anyone is at the sole risk of that person and Bolt and Nut Australia is not responsible for any loss claim or damages arising therefrom.