Timken RAK 7/8 Pillow Block Bearing Cast Iron Eccentric Collectible

Industrial Collectible Bearing

This Timken RAK pillow block bearing is a new-old-stock cast-iron unit preserved as a piece of industrial memorabilia. It displays the classic eccentric locking collar and double-sealed radial ball insert that made the series a staple on line shafts and conveyor frames. Collectors of power-transmission hardware or vintage Timken catalog pieces will recognise the 7/8-inch bore and 5.5-inch overall length as period-correct dimensions.

Mounting And Condition Notes

The housing uses two bolt-through holes on a 4 1/8-inch centre spacing, so a flat surface and standard hardware are all that is required for display or demonstration. Because the insert is factory-filled with NLGI #2 equivalent grease and rated from -65 to 200 degrees F, no re-lubrication is needed for static exhibit; the double seals keep the original lubricant intact. Over-tightening the mounting bolts can distort the cast-iron base, so torque should remain modest.

Operational Limits Of The Design

The eccentric collar locks by friction against the shaft, which suits light radial loads but cannot match the holding power of a set-screw or adapter sleeve on reversing or high-vibration machinery. The alloy-steel balls and cast-iron housing share a 200-degree F upper temperature ceiling, beyond which the grease degrades and clearances shift. At the -65-degree F lower extreme the lubricant stiffens, increasing drag until the assembly warms up.