Makita O-RING 27 HR4511C - 213981-1

Makita 213981-1 — Genuine Makita O‑ring 27

Restore the seal in your Makita rotary hammer with this genuine Makita O‑ring (part no. 213981-1). It’s the rubber sealing ring used on the piston/cylinder/striker area of Makita rotary hammers, listed in Makita parts diagrams as “O‑RING 27.”

Fits Makita Models : HR4510C / HR4501C and  HR4511C rotary hammers.

Key details: nominal inner diameter 27 mm (designation “27”), which in standard metric O‑ring sizes corresponds to a 3.0 mm cross‑section (giving an outer diameter of about 33 mm) — the common metric 27×3 O‑ring profile. It’s a precision rubber sealing ring made to sit in the cylinder/striker groove and keep lubrication in while keeping dust and debris out.

Packaged/sold as the single replacement O‑ring called out in the Makita parts list; replace the worn or perished ring to restore impact consistency and prevent internal leakage.

(If your model’s parts diagram shows 213981‑1, this is the original Makita replacement to use.)

Jump straight to the Makita spare parts diagrams:

• Makita HR4501C Parts
• Makita HR4510C Parts
• Makita HR4511C Parts

Browse our full range of Makita hammer drill parts.