RIDGID R86047B: problems, parts and running costs

Checked: 2026-10-09

Summary

The main caution is a single Reddit report of a 7/8 in. wheel in a box labeled for a 5/8 in. arbor, plus a tool that slows under heavy pressure and is meant for light-to-medium work. There are no subscriptions; running costs are the separate 18V battery and charger plus consumable Type 27 wheels. At $139 from Home Depot it is a reasonable compact grinder for users already on the RIDGID 18V platform.

Common problems and fixes

• Wheel/arbor packaging mismatch — one r/Ridgid owner reports a 7/8 in. wheel included despite a 5/8 in. arbor label; check the wheel on arrival. Not a warranty issue unless the part is defective. [8]
• Slows under heavy pressure — the tool is not intended for the heaviest applications and slows compared with larger cordless grinders; heavier jobs call for a larger class of tool. Not a warranty issue. [2]
• Only Type 27 wheels allowed — the manual forbids Type 1 straight or cutoff wheels, and no separate cut-off shroud is included. Not a warranty issue. [3][2]
• No variable speed — the tool has no electronic speed control. Not a warranty issue. [6]
• Manual registration confusion — RIDGID’s manual search for R86047B returns a drill-driver manual; the correct grinder manual is the Home Depot PDF. Not a warranty issue. [10][3]

Parts and consumables

• Type 27 depressed-center grinding wheel — 4.5 in. diameter, 6 mm thick; one is included in the box. Replacement cost is not reported in the sources. [1][3]

Yearly running cost

Not enough data for an annual figure. Recurring costs are consumable Type 27 grinding wheels plus the separate 18V battery and charger if not already owned. There is no subscription or consumable lock-in.

When it is a good buy

• The Home Depot category listing shows $139.00 for the bare tool, the product page shows $149.00, the R86047K kit with a 4.0 Ah battery and charger is $219.00, and Pro Tool Reviews reported $159.00 in August 2022. [11][4][2]
• At $139: competitive for light-to-medium grinding and cutting on the RIDGID 18V platform, with 9,000 RPM brushless performance and tool-free features. [11][2]
• At the older $159 price: value is thinner against newer competitors. [2]
• Heavy or all-day users should consider larger cordless or corded grinders. [2]
• No specific competing models are named in the sources.

Sources

• RIDGID 18V Brushless 4-1/2 in. Paddle Switch Angle Grinder R86047B — official product page
• Operator’s Manual — 18 Volt 4-1/2 in. Brushless Angle Grinder R86047 (PDF)
• RIDGID 18V Brushless Cordless 4-1/2 in. Paddle Switch Angle Grinder R86047B — The Home Depot product page
• RIDGID 18V Brushless Cordless 4-1/2 in. Paddle Switch Angle Grinder R86047B — The Home Depot Canada product page
• RIDGID 18V Brushless Cordless 4-1/2 in. Paddle Switch Angle Grinder (Tool Only) — powertools.ridgid.com
• More Accurate Metalwork! Ridgid 18v Brushless 4.5in Paddle Switch Angle Grinder — YouTube
• Angle Grinder for cutting? — Reddit r/Ridgid
• RIDGID 18V Brushless Cordless 4-1/2 in. Angle Grinder Kit R86047K — Home Depot Q&A
• RIDGID Powertools Product Manuals search for R86047B
• RIDGID Angle Grinders — The Home Depot category listing