5/16" Ball Bearing - 3/16 diameter integrated 3/8 Long Axle Outer Diameter - 1 55/64 inch (1.859375") the 6906ZZ inner diameter is

the 6906ZZ inner diameter is 30mm

With a uniform 1/2" cross-section

S61903 Open ABEC-5 Ball Bearing

Racing Go Kart Axle 50mm

5/16" Ball Bearing - 3/16 diameter integrated 3/8 Long Axle Outer Diameter - 1 55/64 inch (1.859375") the 6906ZZ inner diameter is5 16" Inch Ball Bearing with 3 16" diameter integrated 3 16" Inch (4. 76mm) Pin Diameter 3 16" x 5 16" x 3 8" Inch 5 16" inch (7. 94mm) Ball Bearing with 3 16" inch (4. 76mm) diameter integrated 3 8" inch (9. 53mm) Long Axle, Pin Diameter is 3 16" inch, Bearing Outer diameter is 5 16" Inch (7. 94mm), and Width of the assembly is 3 8" Inch (9. 53mm Long), made from durable 52100 alloy steel, commonly known as chrome steel. 3 16" x 5 16" x 3 8" Ball