Genuine Makita 213429-3 — rubber O‑ring marked "O RING 27" (nominal inner diameter 27 mm).

This sealing ring keeps dust, grit and lubricants where they belong inside the hammer housing and piston/bit area, helping prevent premature wear.

Commonly listed for Makita demolition hammers in the HM1100 and close relatives — examples include HM1100, HM1100C, HM1130 / HM1130C and HM1140C.

Sold individually as a genuine Makita spare parts item, the 213429-3 is a simple, direct replacement if your existing ring is cracked, flattened or brittle; install the new 27 mm O‑ring to restore the tool’s seal and performance.

Jump straight to the Makita spare parts diagrams:

• Makita 1100 Parts
• Makita HM1100 Parts
• Makita HM1100C Parts
• Makita HM1130 Parts
• Makita HM1130C Parts

Browse our full range of Makita hammer drill parts.