# DB, DF, and DT Arrangements Before You Set Preload

Back-to-back (DB) stiffens moment loads; face-to-face (DF) tolerates misalignment; tandem (DT) stacks thrust in one direction. Preload arithmetic changes with each layout because the effective spring path through the races differs. Matched sets arrive with ground spacers—do not swap rings across boxes.

Confirm the arrangement against spindle-bearings.com before cutting a new spacer. Preload calculation for spindle bearings maps DB/DF/DT to stiffness and thermal behavior.

Shandong TFL Bearing Co., Ltd keeps matched-set handling rules next to the calculation examples for rebuild crews.