They have special characteristics which steel bearings do not have such as being non-magnetic or insulating
RNFCL2525A3 NSK Ball Screw
The Bearings part number is B71909-E-T-P4S-UL and This bearing has the following Dimensions: B71909 E T P4S UL 45x68x12 mm
Acting Type Single Acting - Pull Airtac ttg Stopper Cylinder Single Acting (Pull) Adjustable for Height Airtac Product Series Airtac TTG Stopper Cylinder Single Acting - Pull Adjustable Height Bore Size 50mm Brand Airtac Component Type Pneumatic Stopper Cylinder Magnet Without Magnet Stopper Type Roller Stroke Length 30mm Thread Type G
MI20X160UG
Airtac Round Body Air Cylinder, Double Acting Pneumatic Fittings and Tubing Connectors They have special characteristics whichMI20X160UG Airtac Round Body Air Cylinder, Double Acting Round body pneumatic cylinder, double acting, Stainless Steel, 20 mm bore size, 160mm stroke, without magnet, Perpendicular 90 degrees back cover, G thread type Acting Type Double Acting Airtac mi Round Body Air Cylinder Stainless Steel ISO6432 Airtac Product Series Airtac MI Round Body Air Cylinder Stainless Steel ISO6432 Back Cover Type Perpendicular 90 Degrees Bore Size 20mm Brand Airtac