Model#: MILN2780-20

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Brand new items;Full manufacturer warranty available
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New items with possible minor cosmetic damage; CPO 120 day money back guarantee
Returned items inspected, repaired and tested by CPO technicians; CPO 60 day money back guarantee

Milwaukee 2780-20 M18 FUEL Lithium-Ion 4-1/2 in./5 in. Paddle Switch Grinder (Tool Only)

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  • Note: Battery & Charger sold separately
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In Stock Delivered by Wed., Sep.18

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Product Overview


The world's first cordless grinder delivers the power of a corded grinder with up to 2X more run time and up to 10X longer motor life. The M18 FUEL 4-1/2 in. / 5 in. Grinder supplies maximum sustained power to complete the toughest grinding, surface preparation and cutting applications. The POWERSTATE Brushless Motor provides up to 10X longer motor life and lower cost of ownership. The M18 REDLITHIUM XC5.0 Battery Pack (not included) delivers up to 4X more run time and 20% more power. The grinder features REDLINK PLUS Intelligence, the most advanced system of cordless power tool electronics, for maximum performance. The 18V lithium-ion grinder's thin body design gives it optimized balance to rest easily in your hands. Tool-free accessory changes and guard adjustments mean less downtime during work. The grinder is built with the same tool body, gearing system and anti-vibration side handle as Milwaukee's legendary high-performance corded grinders for maximum durability on the job. Grinding wheel sold separately.
  • POWERSTATE Brushless Motor: Delivers maximum power and up to 10X longer motor life
  • REDLINK PLUS Intelligence provides optimized performance, electronic clutch, and overload protection using total system communication between tool, battery and charger
  • REDLITHIUM XC5.0 Battery Pack (not included) provides superior pack construction, electronics, and performance to deliver 2X more run-time and more work over pack life
  • POWER TO GRIND: World's first cordless grinder with corded performance
  • DURABILITY: Same metal housing & gearing system as legendary high performance corded grinders
  • 100% tool free: Make all accessory changes and guard adjustments without a wrench for increased productivity
  • Paddle-switch design: Provides increased comfort and ease-of-use when operating in various positions
  • M18 FUEL Lithium-Ion 4-1/2 in./5 in. Paddle Switch Grinder -2780-20
  • Tool Only - Batteries and Charger Sold Separately


Series: FUEL
Cordless: Yes
Length: 15 in.
Width: 3.27 in.
Height: 8.58 in.
Weight: 5.8 lbs.
Arbor Size: 5/8 in - 11
Batteries Included: 0
Battery System: M18
Battery Type: Li-Ion
Bluetooth Compatibility: No
CSA Safety: Yes
Case Included: No
Charger Included: No
ETL Safety: Yes
Motor Type: Brushless
No-Load Speed (RPM): 8500
Powered Tool Power Source: Electric - Cordless
Spindle Thread: 5/8 in - 11
Switch Settings: Dead Man
Switch Type: Paddle
UL Safety: Yes
Variable Speed: No
Voltage: 18V
Wheel Diameter: 4.5 in / 5 in
Wifi compatibility: No



4.7 / 5.0
251 Reviews
5 Stars
4 Stars
3 Stars
2 Stars
1 Star
Yes, I would recommend this to a friend (37)
Easy To Use (34)
Powerful (32)
Ergonomic Design (30)
Value (7)
Heavy (1)
Short Run Time (if applicable) (1)
Best Uses
Small Projects (9)
Jobsite (9)
Frequent Use (8)
Home Repair (7)
Products cuts out and over heats every time
It’s a nice design and I have a lot of m18 products and love everyone and use almost all of them every week but every time I go to use the grinder it cuts out and won’t let me use it agin until it cools off, I’m not even putting much stress on it just cutting through 24 gauge sheet metal and I can’t cut 2 inches without it cutting out...
August 26, 2019
Originally posted at
Another great Milwaukee tool for the bag
When you need a certain tool you can often get away with choosing from a variety of tools but when you need a grinder you need a grinder. This Milwaukee is powerful yet the battery lasts long enough to get through the job.
August 24, 2019
Originally posted at
I would buy this product again if I ever need to.
Normal grinder applications I do alot of wood work so use a great many grinder disks. The removable dust screen is a great idea.
August 21, 2019
Originally posted at
I use this grinder everyday it is simply amazing no need to Cary a genset or extension cords anymore.
From up in a man basket to down under cat walks can get everywhere and with the 5.0 batteries it last a long time I also use it for wood working and it is awesome thank Milwaukee.
August 21, 2019
Originally posted at
Love this paddle grinder
Bought this to replace my corded grinder that kept cutting out on me. I bought the set in the hard plastic case, which was worth the extra $. In this case there is enough room to carry a set of replacement disks which is nice. Sometimes I’m grinding concrete and sometimes steel, this grinder does whatever you put it up against. With the side handle and movable guard it is very comfortable but heavy duty to use. I would buy this again without any hesitation. Great tool Milwaukee thanks!
Steve F.
August 18, 2019
Originally posted at
Who doesn’t know about Milwaukee by now?
Amazing portable grinder! I have 2. Need to get one more.
August 17, 2019
Originally posted at
Great tool
Great tool from cleaning up areas for welding or to cutting anything from bolts to steel very useful and dependable
August 16, 2019
Originally posted at
It's okay but expected better.
I've been using this to cut thick metal, large objects. I kinda like the paddle but needs to get use to it. What I don't like about it that it cuts out when being pushed even a little. I was expecting this tool to exceed my Ryobi brushless angle grinder. It does a little better but I expected more.
August 16, 2019
Originally posted at
My new M18 Fuel Milwaukee grinder
I love this new grinder. It is light weight easy to use and does a great job. the battery lasts a long time. I also love the fact I can take it anywhere.

These Milwaukee tools are incredible. I have bought a few different ones now and wish I could afford to buy them ALL!!!!
August 16, 2019
Originally posted at
I like it because it is like having two grinders in one
August 16, 2019
Originally posted at

Questions & Answers

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Browse 10 questions Browse 10 questions and 12 answers
Is this compatable with the HD9.0 battery?
Jimmy S on May 29, 2019
BEST ANSWER: It is compatible with any M18 Milwaukee battery. The heavier 9.0 battery could make it a "handful," affecting the balance of the grinder.
Will this work with a normal 18v battery or does it have to be the XC 4.0
Ross on Dec 23, 2014
BEST ANSWER: The grinder will work with any M18 series battery
if these are so good how come they have recondition ones already ?
A shopper on Sep 29, 2018
BEST ANSWER: Your question will be best answered by the manufacturer, who can provide you with the accurate information. The number to reach the technician directly is 1-800-729-3878 or online at
Does it come with a case or bag?
A shopper on Aug 17, 2018
BEST ANSWER: The item will not include any case or bag.
You said milwaukee has a 5 year warranty i bought my milwaukee grinder 8 months ago it stopped working can I send it to y'all warehouse and get a replacement or how will that work? thank you
chino on Sep 13, 2017
BEST ANSWER: Milwaukee warranties will need to be handled through the manufacturer directly. They can be reached at 800-729-3878. From there you will be referenced to a service center in your area
What is the warranty on this item?
waylon on Dec 10, 2015
BEST ANSWER: Milwaukee offers a 5 year warranty on this tool.
I bought this tool to use on a log home sanding large pillar logs.

Where can I find/buy the accessories to do the job? Sanding disks, backing pad, spindle, disc nut, etc??
Thanks for the help
Rod on Sep 16, 2014
BEST ANSWER: Please contact the manufacturer direct at 1-800-729-3878 for a service/parts center in your area.
where can I find the flange nut kit for the milwaukee 18volt cordless grinder?
A shopper on Apr 20, 2018

New Vs. Reconditioned

What's the difference between New and Factory-Reconditioned?

Factory-Reconditioned products have been returned to the manufacturer and are restored to like-new operating condition; they go through a rigorous testing and inspection process. Plus, they offer a significant savings vs. new.
  • Reconditioned products may have minor cosmetic blemishes or scratches that do not affect item performance.
  • Reconditioned products may not come with all of the consumables the new version comes with (bits, sanding pads/papers, cases, etc.).
  • Both come with a manufacturer warranty and are covered by our Money Back Guarantee; New is 30 days, Reconditioned is 120 days.
Condition: New Factory Reconditioned
Features: Same Same
Specs: Same Same
Includes: M18 FUEL Lithium-Ion 4-1/2 in./5 in. Paddle Switch Grinder -2780-20,
Tool Only - Batteries and Charger Sold Separately
M18 FUEL 4-1/2 in. - 5 in. Paddle Switch Grinder (Tool Only) -2780-80,
Flange Nuts,
Wheel Guard,
Spanner Wrench,
Tool Only - Batteries and Charger Sold Separately
Availability: In Stock Out of Stock
Warranty: 5 Year 1 Year