Plain Linear Bearing Pillow Block PN08 1/2" OpenOpen Plain Linear Bearing Pillow Block with a 1 2" inner diameter and a precision running clearance of 0. 0005" per side. A mountable standard sized aluminum housing encloses the bearing, which features a self lubricating FrelonGOLD liner for maintenance free operation in harsh conditions like extreme temperatures, dirt and vibration. Liner options: corrosive resistant FrelonJ & FDA compliant FrelonW Anodized Aluminum Bearing Shell Aluminum Alloy