WoodRiver Brass Knurled Thumb Nut Knobs can be used when
space is a concern and finger tightening is adequate for light-duty clamping. 9/16″-diameter,
3/8″-high thumb nuts fit easily in confined spaces. Vertical splines
around the rim of the nut makes it easier to tighten by hand. 1/4″ – 20
coarse thread; six pieces per package.