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Ryobi P423 vs P421 Review

If you are in need of a product that can cut, grind, and sand very easily, you may want to invest in a grinder. Grinders are excellent for many tasks and can work with a variety of materials, in order to help you get through projects easily and quickly. Ryobi makes two very similar grinders that have a few key differences you should know about. Let’s take a look at both, and see which one would be the best fit for your needs.

Ryobi P423 18V One+ Grinder and Metal Cutter w/ Adjustable 3-Position Side Handle and Onboard Spanner Wrench (Battery Not Included, Power Tool Only)

Ryobi P423
Ryobi P423

The Ryobi P423 grinder is a streamlined grinder that weighs only 4.35 pounds to make long jobs much easier to handle. This grinder takes 4-1/2 inch grinding wheels, and comes with a brushless motor for added battery conservation, runtime, and longer motor life.  This product features a 3-position side handle that makes it excellent for difficult to reach areas.

This product works with Lithium+ HP batteries for better performance, and can easily move from cutting to grinding applications. This product also comes with a compact design, and has an over-molded grip for optimal comfort while using the product. This grip also prevents slippage during rough weather conditions.

The Ryobi P423 also comes with an onboard spanner wrench, which can be stored on the grinder, so your disc replacements are simple and easier. This product features guard adjustment that is tool free, which allows you to make fast adjustments with ease. It works with a simple push of a button, and allows you to work with protection at a variety of angles.

This product can cut through PVC, welded metals, piping, and many more materials with ease. The Ryobi P423 comes with a 4-1/2 inch wheel for your convenience, but does not come with an 18-volt battery. The battery will have to be purchased separately. This product comes with a lock on switch, as well as a spindle lock for added ease of use.

More features of the Ryobi P423 Grinder

  • Maximum speed of 10,400 RPM
  • Arbor size of 5/8 – 11 UNC

Ryobi P421 ONE+ 18V Angle Grinder with Intelliport Duel Chemistry Charger and ONE+ 18V Lithium-ion battery

Ryobi P421
Ryobi P421

The Ryobi P421 grinder is very similar to the previous product, as it is also lightweight at 6.18 pounds and comes with a narrow design. This product also takes a 4-1/2 inch-grinding wheel, and it is included for convenience. This product comes with a brushed motor, and features a 3-position side handle as well.

This product also works with an 18-volt Lithium-ion battery, but the batteryisn’t included like the previous product and must be purchased separately. The Ryobi P421 also comes with an onboard spanner wrench for convenience. This wrench can be stored on the grinder so you don’t have to worry about losing it.

The Ryobi P421 also comes with a tool free guard, so that you can easily and quickly adjust your guard positioning and get back to working. This product features an over-molded grip as well, to make working in harsh conditions much easier.

With an intuitive trigger switch, the Ryobi P421 also includes a spindle lock for ease. This product, much like the P423, can also get through tough materials such as metals, PVC, and piping.

More features of the Ryobi P421 Grinder

  • Maximum speed of 6,500 RPM
  • Arbor size of 5/8 – 11 UNC


If you prefer a grinder that has a higher RPM, is lighter weight with a brushless motor, includes a lock on switch, and has great durability, then the Ryobi P423 may be the best choice for your needs. Alternatively, if you prefer a grinder that has a brushed motor, with an intuitive trigger switch and a similarly great durability, then the Ryobi P421 may be a better choice for you. Both of these products offer tool-free guard adjustments, 18-volt batteries, and the same arbor size. Either of these products would be a great choice for your grinder needs!

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