Trunnions

Trunnions are the cast metal pivoting brackets a table saw's arbor and motor assembly are mounted to, riding on curved tracks bolted to the underside of the saw's table -- they're what actually tilts the blade for bevel cuts and raises or lowers it for depth, via the height and tilt handwheels on the front of the saw. Because the trunnions are what physically locate the blade relative to the table, wear, damage, or misalignment there is a common real cause of a saw that won't hold a true 90-degree or 45-degree blade angle, or that develops play and vibration over years of use.

It's a part most casual users never think about until something's genuinely wrong with a saw's accuracy -- realigning or replacing trunnions is a real repair, not routine maintenance, but knowing the term helps when researching why a saw's blade angle keeps drifting.