Kickback is one of the leading causes of table saw injuries. It happens in two ways: when the wood kerf closes up behind the blade during ripping and pinches the blade, or when workpieces pivot into the blade’s rear teeth. Either way, the blade lifts and fires them back at the operator with great force. But, thanks to revisions to Underwriters Laboratories UL 987 Standard for Stationary and Fixed Power Tools, all table saws designed after 2008 must now have a riving knife that rises and falls with the blade instead of a fixed-position splitter.
Its close and constant proximity to the teeth greatly reduces kickback from happening. UL also stipulates that the guard must attach to a riving knife-style spreader that rises and falls with the blade. And, the system must be easy to install and remove. Either the riving knife or the guard/spreader can be left on the saw for most cutting operations except dadoing.