Your best defense against a stuck fastener is to use an impact driver. I use mine on rotor bolts, left engine side cover screws, cam cover bolts, valve cover bolts, etc. The driver works by spring tension. As you strike the end with a hammer, the impact driver pushes in an rotates anti-clockwise, thus loosening the fastener. The 3/8″ socket drive head has an attachment for included philips and standard-head fasteners. The casing is wrapped in a grippy orange rubber to prevent slipping. To loosen allen-head fasteners, use your own allen socket set, or ours.