Ryobi P423 18V One+ Brushless 4-1/2″ 10,400 RPM Grinder and Metal Cutter w/ Adjustable 3-Position Side Handle and Onboard Spanner Wrench (Battery Not Included, Power Tool Only)

(10 customer reviews)

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ONBOARD SPANNER WRENCH: Simplify your disc replacements. This spanner is stored on the grinder, so you don’t have to worry about losing it when you’re switching discs out for multiple applications

3 POSITION SIDE HANDLE: Whatever angle you’re attacking your job from, you’ll be able to get the optimal leverage with the help of the onboard plastic handle that adjusts as you need it

COMFORT GRIP HANDLE: A rubber overmold covering the grip keeps up the friction between the tool and your hand, allowing for precise work in slippery environments

TOOL-FREE GUARD ADJUSTMENT: If you need to adjust the depth or angle of your cuts to suit different materials, you can do so with the push of a button

ONE+ COMPATIBLE: This 18V cordless power tool from Ryobi works with the 18V batteries in Ryobi’s lineup. These models include the P100, P102, P103, P104, P105, P107, and P108

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SKU: B077MLHM73 Category:

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Product Warranty: For warranty information about this product, please click here


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Part Number


Item Weight

‎4.35 pounds

Product Dimensions

‎12.5 x 5.75 x 5.5 inches

Item model number


Is Discontinued By Manufacturer




Power Source



‎18 Volts

Item Package Quantity


Batteries Included?


Batteries Required?






Customer Reviews

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Best Sellers Rank

#53,717 in Tools & Home Improvement (See Top 100 in Tools & Home Improvement)#56 in Power Angle Grinders

Date First Available

November 20, 2017

10 reviews for Ryobi P423 18V One+ Brushless 4-1/2″ 10,400 RPM Grinder and Metal Cutter w/ Adjustable 3-Position Side Handle and Onboard Spanner Wrench (Battery Not Included, Power Tool Only)

  1. T.M.

    Came in a plain unmarked brown box instead of the normal Ryobi retail box, but seems to be new and in perfect condition. I almost subtracted a star for the brown box, but I really like the tool so I left it at 5.It included two discs, one grinding and one cutting, both 4.5 inch 7/8 arbor. It also included two “wheel guards” one for grinding and one for cutting.I couldn’t find any info in the manual about compatible disc sizes, but here’s how it appears to me:Although it has a 5/8 arbor (5/8 by 11 UNC) it also can use 7/8 discs with the included step washers. In fact the two included discs are both 7/8.I bought some 4 inch 5/8 arbor discs (with plain unthreaded hole) to go with it since the listing said 5/8 arbor, and they seem to work fine. It looks like it should also work with 5/8-11UNC discs since that is the thread of the arbor, but I don’t have any so I haven’t tried. The 5/8 plain hole discs are probably the worst choice since they ride on the threads. The 7/8 discs ride on the step of a step-washer, so the the disc is not in contact with the arbor threads. That and the fact that it came with 7/8 discs tells me that 4.5 inch 7/8 arbor discs are the preferred choice.

  2. Left Coast Geek

    I’ve had a 5″ AC corded angle grinder for years, very handy tool, I use both rust stripper disks, cutoff disks, and grinder disks… had a job to do where there was no access to power, I needed to cut 2 feet off the top of a T-Post that was already in the ground … Since I already have a few Ryobi tools, and the battery+charger, I picked this up, and it did the job, felt nearly as powerful as the plug-in Dewalt, and in a matter of a minute or so, cut through that steel T-post nicely.The spindle lock for changing disks was a bit hard to use, you have to firmly press it in, while rotating the disk all around til you find the hole and it drops in. when manually rotating the disk, it did a sort of cogging thing which made me wonder if it was OK, but once the disk was installed, and I fired it up, it ran just fine.suggestion when using one of these, never hold it so your face is in the same plane as the cutting disk, and wear heavy leather work gloves, those disks can shatter and at 10000 RPM, they throw off pieces HARD.

  3. locohefe

    This this is a beast ! I’m so glad ryobi offers a high end cordless grinder as the cheaper one isn’t worth messing with. This model P423 on the other hand is pretty impressive. It has the highest rpm of any cordless I could find and at 10,400 rpm it has almost the power of a corded grinder. And it shows. Of course a cordless grinder is not meant for very heavy jobs. That is where a corded tool comes in to play. But for quick cuts and grinding of tacks and welds this thing can’t be beat. The only thing my DeWalt has over this grinder is battery run time.. If you’re invested in the Ryobi cordless tool series you need this grinder period.

  4. Jason

    This is a great grinder, just make sure your batteries are fully charged as it eats them up quick when cutting heavy steel. Use good discs, cheap ones will take longer to cut and run your batteries down faster.

  5. Melsman

    This is a great tool! However, don’t expect to use this tool with the smaller 2Ah battery; you need to use the larger 3Ah (or larger) battery. With the smaller battery, the tool draws too much power under sustained load and the low voltage protection shuts the tool off – very frustrating. However, using the more powerful 3Ah battery solved the issue completely.

  6. Amazon Customer

    pick your brand and standarize. i like ryobi. i used the 14.4 v ryobi for over 20 years with no issue, although i have used up lots of batteries as they aged out. i am now finally converting over to 18 v stuff and just like my older ryobi stuff the new equipment is outstanding. the 18v lithium batteries really last and the motors are that much stronger so i use my battery powered stuff as my first choice for lots of minor to medium heavy work. over time i will fill up the shop with the 18 v stuff as I need to add additional tools

  7. VINNY

    The grinder is great, this is my second, the first fell off a roof but was working great after a year of hard use. This was to be it’s replacement. Works great for tuckpointing prep, had no problem cutting through cast iron (lenox blade), stone, tile etc. The problem you may run into is you may receive tool in a plain brown box. some sellers will say refurbished which is fine. Ended up purchasing at a big box store. For the money it’s a great grinder.

  8. J. E. Lewis

    This is a good grinder that works quite well for the kind of occasional small jobs that I normally need a grinder for at home. For doing things like building trailers and other constant work you’ll need a corded grinder because it eats up batteries pretty fast. The only downside is the grip is a bit thick for my hands. It works, but a smaller form factor would make it easier to hold on to. Aside from that the wrench storage in the side handle is a very nice touch. When I received the grinder the wrench would easily fall out – hardly any retention whatsoever. This was fixed in seconds by putting a very slight bend in the wrench using my vise and gentle hand pressure. This gives it enough friction to stay in the handle slot.

  9. TROY

    I was expecting “ok performance” but this thing is a workhorse


    I initially had problems with it shutting down after about a minute. I thought a safety or something was the problem. I used one of my reliable 4ah batteries and GAME ON! I LOVE IT! It’s like the heavy duty Dewalt that I used before. Cut some rebar a couple of day ago. LIKE BUTTER! Highly recommend this tool!

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