Sizing a Tufnol bush follows normal engineering practice with two laminate-specific allowances. Aim for a length-to-shaft-diameter ratio of about 1:1 (long bearings over 2:1 trap heat), keep wall thickness modest to help dissipate heat, and set the initial running clearance to allow for the small dimensional growth as the laminate absorbs moisture and for bore closure when a bush is press-fitted. The exact clearances and worked allowances are set out in the bearing dimensions calculation guide.