Ruland Manufacturing has expanded its line of shaft collars to include a double-wide version with bore sizes from 3 to 25mm, which can also be used as a compact rigid coupling. They are offered in one-piece or two-piece clamp styles from high strength aluminium, lead-free black oxide carbon steel, and stainless steel. A cross cut facilitates their use as a compact rigid coupling, enhancing its holding power when there is a small variation in shaft size due to tolerances. Their compact design reduces inertia - an important consideration in motion control applications - and makes them suitable for limited space applications.