Threaded spacers, sistance bushes, spacer sleeves

Cylinder head covers – Catalogue Page 7
... During assembly, spacer sleeves ensure a creep-free and captive connection and prevent cracks or even breaks in the plastic... Based on a design sealing gap of 1 mm (0.0394 in), the precise functional dimensions and the number of bolts for the isolating system can be determined

Super Precision Bearings – Catalogue Page 169
... in the drawing, both spacer sleeves should have the same length... For this purpose, the side faces of the two sleeves should be ground in one chucking. 168 ... recommendations for machining outer spacer sleeves Dimensions in mm 250 315 315 400 Tolerances in μm –17 –49 12 8 6 1,6 –18 –54 13 9 7 ...