Hitachi 980877 — Genuine Hitachi Belleville (disc) spring, part number HIT-980877. This small conical (disc) spring is the replacement spring used in the clutch/impact assembly of Hitachi rotary hammers: it provides axial preload in the clutch stack so the slip-clutch and hammering action operate smoothly and consistently. It’s supplied as the single disc spring (fits into the clutch/spring-plate area) and is a direct, original Hitachi replacement for affected models.

Example models this part fits (typical): DH30PC2, and it’s also listed for several DH25/DH28-series rotary hammers (DH25PA, DH25PB, DH28PC, DH28PD) and some related Hitachi/Hikoki tools such as VB13Y in parts diagrams. Use these model examples to verify fit for your tool.

Why this part matters: a worn or broken Belleville spring will let the clutch slip at the wrong torque or degrade hammer performance; replacing it restores correct clutch preload and reliable impact action without having to replace larger assemblies. The part is sold individually as the original Hitachi disc (Belleville) spring, part code HIT-980877.

Note: check your tool’s parts diagram for the exact part location and quantity required (many rotary-hammer diagrams show the Belleville spring adjacent to the clutch plate and spring plate).