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

Model: miln2781-20
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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
15 in.
3.27 in.
8.58 in.
5.8 lbs.
Arbor Size
5/8 in - 11 in
Batteries Included
Battery System
Battery Type
Bluetooth Compatibility
CSA Safety
Case Included
Charger Included
ETL Safety
Motor Type
No-Load Speed (RPM)
Power Source
Spindle Thread
5/8 in - 11 in
Switch Settings
Switch Type
UL Safety
Variable Speed
Wheel Diameter
4-1/2 in / 5 in
Wifi compatibility

Reviews :

4.8 / 5.0
118 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)
Yep, I'll keep it.
Its another item on the road to converting the entire plumbing truck to cordless. Ive had the grinder out of the truck a few times now, ranging from cutting thru ceramic tile to install a range hood (with the addition of the milwaukee portable wet/dry vac to control duct or with a flap wheel to debur and sculpt aluminum channels where shower enclosures meet irregular tile. This grinder fits nicely in the tool bag with the impact driver and hammerdrill/driver that go on nearly every jobsite.
My only request would be a variable speed option on the next version as I have on occasion a need to drill hard porcelain or stone tile and counters with a diamond end mill. They must run slow or with water cooling to survive. I'll keep my eyes open for that model, our countertop division will buy one for each truck in a flash.
March 23, 2020
Originally posted at
I would buy this product again
Light weight, easily does the task at hand. Great power to get the job done.
March 22, 2020
Originally posted at
I would buy it again it need be
This works really good for us. Having this power in a cordless really helps. I am using a 9Ah battery on this and it does get the job done.
March 14, 2020
Originally posted at
Great product
The only down side is that it vibrates a little too much when on, besides that everything else is great. Very reliable product
March 14, 2020
Originally posted at
This product works awesome for cutting and grinding, works just as hard as a plug in one
March 8, 2020
Originally posted at
Good power, good solid feel
Love the torque when you turn it on, and the ability to leave it running as i work!
February 23, 2020
Originally posted at
I would buy this again...
I like the grinder just not the location of the lock on.
February 23, 2020
Originally posted at
The most used tool in my shop
Absolutely amazing grinder! I can't say enough good about this grinder
January 27, 2020
Originally posted at
Great grinder. Purchased it for a job I needed and it worked flawlessly.
January 25, 2020
Originally posted at
I would buy it again!
I am field service tech and this works great for fabrication projects. Great tool
January 18, 2020
Originally posted at

Q & A :

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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.