DeWalt 1004691-64 — original DeWalt spring washer (4 mm) designed for the crankcase / gear area of SDS rotary hammers. This compact spring washer (listed as "WASHER‑SPRING 4mm") is a direct-fit replacement part that restores proper axial preload and retains internal components during reassembly.

Common-fit examples from parts diagrams and service lists include Stanley / Stanley FatMax FME1250 (Type 1) and related KFFMED1250 / Black+Decker KD1250K (Type 1) rotary-hammer assemblies — check your tool’s parts breakdown to confirm exact placement before installing.

If you need a single, reliable replacement to complete a repair, this original DeWalt washer spring is the small internal part that keeps the crank / gear components seated correctly; it’s one of the genuine DeWalt parts you’ll want on hand when working on rotary hammers. This item is shown in power tool parts for those models.