Makita 266163-4 Spare Part - CUP SQUARE NECK BOLT M6x80

Genuine Makita part 266163-4 — cup (cup-style) square‑neck bolt, M8 x 80 mm. This original Makita bolt is the correct replacement fastener used where a square neck under the head must lock into a mating bracket (so the bolt won’t rotate while you tighten the nut).

Purpose and fit: Designed to secure the side/auxiliary handle and related brackets on Makita rotary hammers and similar tools — listed fitment includes models in the HR3000/HR3500/HR4000/HR4500/HR4510/HR4511 series (examples: HR3000C, HR4001C, HR4000C, HR4511C). Use this when the original handle bolt is bent, the head/neck is damaged, or the threads are stripped.

Key details you’ll care about for a repair:

- Size: M8 × 80 mm — provides the correct shank length and thread engagement for the handle assembly.

- Head/neck style: cup head with a square neck under the head to seat into the bracket and prevent rotation during tightening.

- Condition & unit: sold new as an original Makita part (single bolt), so you get the same specification as the factory fastener.

Installation tip: make sure the square neck fully seats in the bracket recess before torquing the nut; replace if the neck is rounded or threads are damaged so the handle clamps securely and safely.

This is the original Makita replacement bolt specified for those hammer models and is the fastener you want when restoring the tool to proper, secure assembly.

Browse our full range of Makita hammer drill parts.