WoodRiver Brass Knurled Thumb Nut Knobs can be used when
space is a concern and finger tightening is adequate for light-duty clamping. 3/4″-diameter,
7/16″-high thumb nuts fit easily in confined spaces. Vertical splines
around the rim of the nut makes it easier to tighten by hand. 5/16″ – 18
coarse thread; four pieces per package.