Before you replaace the thmbscrews that hold the blade in the clamps on your dewalt 788 spray a little penetrating oil such as wd40 onto the spinning pieces at the end if those pieces don't spin it can be difficult to tighten a blades properly often a little penetrating oil will loosen up the stuck pieces wipe off the execess oil before trying to clamp a blade the oil can cause your blades to slip
