Original Makita Ring 21 — part no. 257241-1 — replacement retaining ring used in the chuck/guide-washer area of several Makita SDS-plus rotary hammers. It’s the small “Ring 21” listed in Makita parts breakdowns (item 4) that secures the chuck/guide-washer assembly and keeps components aligned during hammering.
Why this part matters: if the retaining ring is worn, cracked, or missing the chuck cover and guide washer can shift under load, causing play, poor bit retention, or accelerated wear to adjacent parts. Replacing it restores the original axial retention and alignment inside the front assembly.
Example models this part is listed for (examples only — check your tool’s parts diagram to confirm): HR2450 and HR2450F, and commonly used in related SDS-plus rotary-hammer models such as HR2440, DHR164/DHR165 and several BHR/HR202x series where the parts breakdown names “Ring 21.”
Notes for repair: the part is cataloged by Makita as “RING 21” (257241-1) and is fitted into a groove behind the chuck cover/guide washer — it’s supplied as a single replacement ring and is intended to be fitted into the front assembly groove; replace any damaged ring before reassembling the chuck cover.
If you need a genuine Makita ring to restore correct alignment and chuck retention, this is the original Makita part used in the front assembly of the models listed above.
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