NB Systems SW4 1/4" inch Ball Bushings Linear Motion SW4:Made in Japan:NB Linear Systems Nippon Bearing Linear Systems SW4 1/4" Bore linear motion ball bushings/bearings, inner diameter(bore) is 1/4" inch dimensions with steelretainer, Bearing is a high accuracy grade linear bushings,series mainly used in the USA, NB brand (Nippon Bearing Linear Systems), made in Japan. ItemNumber of ball circuitsDimensions(Inches)Eccentricityradial clearancebasic load rating drDLBWD1 inchtolerance inch/mminchtolerance inch/mminchtolerance inch/mminchtolerance inch/mmprecision inch/mmhigh inch/mmdynamic CNstatic CoN precisionhigh SW4 4.25000 -.000250 -.00040.50000 -.00045.75000 -.008.51100 -.008.0390.4687.0003 8.0005 12.0001 -3206265