Milwaukee 2781-20 M18 FUEL Lithium-Ion 4-1/2 in. - 5 in. Slide Switch Grinder with Lock-On (Tool Only)

Model: miln2781-20
ratings        (157) Write A Review
free shipping
This item qualifies for
free shipping

Estimates For

alert warning icon

  • In Stock


Milwaukee 2781-20 M18 FUEL Lithium-Ion 4-1/2 in. - 5 in. Slide Switch Grinder with Lock-On (Tool Only) Model: miln2781-20
price for vip customer


Product Features & specs :

Milwaukee 2781-20 M18 FUEL Lithium-Ion 4-1/2 in. - 5 in. Slide Switch Grinder with Lock-On (Tool Only)

The M18 FUEL 4-1/2 in. / 5 in. Slide Switch 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 XC4.0 Battery Pack (Sold Seperately) 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.
  • POWER TO GRIND means the World's first cordless grinder with corded performance
  • Same metal housing and gearing system as legendary high performance corded grinders
  • Thin body design and anti-vibration handle provides optimized balance to rest easily in your hands
  • Tool-free accessory changes and guard adjustments mean less downtime during work
  • 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 XC 4.0 Battery Pack (Sold Separately) provides superior pack construction, electronics, and performance to deliver 2X more run-time and more work over pack life
What’s Included:
  • M18 FUEL 4-1/2 in. - 5 in. Slide Switch Grinder with Lock-On (Tool Only) -2781-20
  • Wheel Guard
  • Flange Nuts
  • Spanner Wrench
  • Tool Only - Batteries and Charger Sold Separately
Power Source
UL Safety
Wheel Diameter
4-1/2 in / 5 in
No-Load Speed (RPM)
CSA Safety
Switch Settings
Wifi compatibility
Batteries Included
Battery Type
Case Included
Bluetooth Compatibility
Motor Type
Spindle Thread
5/8 in - 11 in
Variable Speed
Switch Type
Arbor Size
5/8 in - 11 in
Charger Included
ETL Safety
Battery System
15 in.
3.27 in.
8.58 in.
5.8 lbs.
Warranty Term
5 Year

Reviews :

4.8 / 5.0
157 Reviews
5 Stars
4 Stars
3 Stars
2 Stars
1 Star
Would you recommend this product?
Yes (21)
Powerful (16)
Easy To Use (14)
Ergonomic Design (11)
Value (5)
Heavy (1)
Uncomfortable to Use (1)
Best Uses
Jobsite (8)
Frequent Use (6)
Large Projects (5)
Small Projects (5)
I would buy this grinder again
I use the grinder all around our farm. Way better that using a hacksaw
October 19, 2020
Originally posted at
Great for work and light wait I love it for all custums jobs
October 19, 2020
Originally posted at
This grinder is a beast
Love the way it feels in the hand, lots of power, batterie lasts for a long time. Love the tool
October 17, 2020
Originally posted at
Great tool!
Well built, sturdy and comfortable. Great power to it...a must have in your tool cart.
October 10, 2020
Originally posted at
Awesome grinder
Strong grinder. You will definitely need a higher Ah battery, a 6 will do great. Grab it and get to work without extension cords, Love it
October 10, 2020
Originally posted at
Powerful and easy to use.
I use this to cut tile, grind bolts, and grind concrete. I love it it has plenty of power. I chose the slide switch over the paddle switch due to the fact its hard to cut tile while holding the paddle switch while switching hands and cutting at different angles.
September 14, 2020
Originally posted at
Make your day easier
I would like to say since the purchase of my Milwaukee grinder, my work day has gotten a little easier.Being able cut pre assembled duct work quickly and more precisely than other methods. It is a tool I would recommend to others ,( so they stop borrowing mine) to have in there own gang box when needed.
September 13, 2020
Originally posted at
I find it to be a little under powered, but it works great. Like the paddle trigger better. For the money there's better out there. I'm a Milwaukee fan 90% of my electric tools are Milwaukee. All my battery powered tools are Milwaukee.
August 29, 2020
Originally posted at
I would definitely buy this product again.
Previously owned the basic version of this tool. Upgraded to the Fuel version. Excellent grinder. I originally bought this grinder to use on various projects where I don't always have access to electricity. It quickly became my go to grinder. I don't even carry my corded grinder on the truck anymore as this M-18 version is more than up to the task.
August 29, 2020
Originally posted at
Amazing tool
The battery life is insane!!! I love it. Ill buy other tools from milwaukee
August 24, 2020
Originally posted at

Q & A :

Start typing your question and we'll check if it was already asked and answered. Learn More
Browse 3 questions Browse 3 questions and 6 answers
How long can be used before recharge in production no stop ?
Edwin on Apr 19, 2016
BEST ANSWER: That is a very difficult question to answer, runtime depends on many variables. Without knowing whats being done with the grinder, continous runtime could be anywhere from 30 minutes to a couple hours with the 4Ah battery. Keep in mind, charge time is relatively short, with a couple of batteries you can get alot accomplished with little
The description states "Tool-free accessory changes," but a reviewer said that he needed a tool to remove the flange nut. The downloadable manual also states that a spanner wrench is required to tighten and loosen the flange nut. Also, if accessories can be changed without a tool/wrench, why is one included? Can wheels/accessories be installed and removed without a tool or not?
A shopper on Nov 25, 2017
BEST ANSWER: In almost all cases, you can swap blades without a tool. If the blade is the face, on the back of the head is a lever which unclamps the spindle. It is not enough to flip this lever up; you must flip it all the way forward. When you do, the spindle/arbor tension is released and you can unscrew the spindle-cap/arbor-nut with your fingers. If you don't understand how this works, you will probably overtighten the cap/nut and then need a wrench to get it off again.

So, wheels/accessories CAN be installed without a tool, if you don't go out of your way to make it more difficult than necessary.
Can you interchange the types of Milwaukee batteries with chargers and tools?
Frank on Oct 19, 2015
BEST ANSWER: All Milwaukee 18 volt lithium ion tools and batteries are compatible,so yes everything is interchangeable.