Milwaukee M18 QUIK-LOK Brushless 15-in. String Trimmer, 6.0Ah Kit (3115-21ST)
Milwaukee M18 QUIK-LOK Brushless 15-in. String Trimmer, 6.0Ah Kit (3115-21ST)
Preorder - Est. Ship Date Nov. 16
Product Details
Product Details
Key Features
Overview
The Milwaukee M18 QUIK-LOK Brushless 15-Inch String Trimmer Kit (model 3115-21ST) is a cordless split-boom string trimmer for lawn edging, trimming, and clearing overgrowth. This is a battery-powered string trimmer designed for landscape maintenance and residential yard work. It combines the M18 QUIK-LOK Brushless Power Head (3115-20) with the QUIK-LOK 15-inch String Trimmer Attachment (48-08-2650) and an Easy Load trimmer head.
Milwaukee rates the brushless motor at a maximum of 1.41 horsepower and says it delivers more power than 27cc gas power heads. Line speed tops out at 5,900 RPM, so the trimmer keeps cutting through thick grass and weeds instead of wrapping and slowing. A variable-speed trigger gives you fine control for edging along beds, walks, and fence lines.
The cutting swath is adjustable between 15 inches and 13 inches. Use 15 inches when you are clearing a lot of ground and want to finish in fewer passes; switch to 13 inches when runtime matters more than coverage. The trimmer accepts .080-inch or .095-inch line, and it ships with .080-inch line pre-wound on the head.
The Easy Load trimmer head holds 25 feet of line and, per Milwaukee, can be reloaded in under 30 seconds without taking the head apart. On a crew, that adds up: less time on the tailgate rewinding spools and more time cutting. The motor is mounted at the rear of the boom to balance the cutting head, which gives better control and less strain on your arms and back over a long day.
QUIK-LOK is the reason to buy into this platform. The coupler splits the boom so you can remove the trimmer attachment and put on an edger, hedge trimmer, pole saw, or other QUIK-LOK attachment on the same power head. One motor handles the job of several dedicated tools, which saves money and storage space. The power head also runs on the M18 battery system, which Milwaukee says covers more than 300 tools.
This is the Brushless line, not FUEL. It sits below the M18 FUEL QUIK-LOK trimmers in Milwaukee's lineup but uses the same QUIK-LOK coupler and attachment family. This kit includes the M18 REDLITHIUM HIGH OUTPUT XC6.0 battery (48-11-1865) and the M18 and M12 Multi-Voltage Charger (48-59-1812), which is the battery Milwaukee optimized this power head for, so it is ready to run out of the box.
Who should buy it: homeowners and property managers who want gas-level trimming without the engine, landscapers adding a second trimmer that shares batteries with their M18 gear, and anyone planning to build out a QUIK-LOK setup one attachment at a time.
Clear Overgrowth Without Bogging Down

The brushless motor holds line speed in heavy grass and weeds, so you can keep walking instead of waiting for the head to recover.
- Up to 1.41 maximum horsepower
- 5,900 maximum RPM
- Rear motor balances the cutting head
Pick Your Swath

Set the cutting width to the job: wide for open ground, narrower when you need the battery to last.
- 15-inch swath for maximum clearing
- 13-inch swath for longer runtime
- Accepts .080-inch or .095-inch line
Swap Attachments in Seconds

The QUIK-LOK coupler turns this trimmer into a system. Swap to another QUIK-LOK attachment and the same power head is running a different tool.
- Works with all QUIK-LOK attachments
- One motor for multiple lawn and landscape tools
- Fully compatible with the M18 battery system
What's in the Box
- (1) M18 QUIK-LOK Brushless Power Head (3115-20)
- (1) QUIK-LOK 15-inch String Trimmer Attachment (48-08-2650)
- (1) Easy Load Trimmer Head (49-16-2748)
- Pre-wound .080-inch trimmer line
- (1) M18 REDLITHIUM HIGH OUTPUT XC6.0 Battery (48-11-1865)
- (1) M18 and M12 Multi-Voltage Charger (48-59-1812)
- (1) Bail Handle with 2 Bolts
- (1) Allen Wrench
Key Specifications
| Battery Platform | Milwaukee M18 (18V) |
|---|---|
| Motor | Brushless (not FUEL) |
| Maximum Horsepower | 1.41 HP |
| Maximum Speed | 5,900 RPM |
| Cutting Swath | 15 in. or 13 in. (adjustable) |
| Line Diameter | 0.080 in. or 0.095 in. |
| Line Capacity | 25 ft |
| Trimmer Head | Easy Load |
| Handle Type | D-handle |
| Battery Included | (1) M18 HIGH OUTPUT XC6.0 Ah |
| Charger Included | M18 and M12 Multi-Voltage |
| Shipping Weight | 18.01 lbs |
At a Glance
Compatibility
Built For
Pro Tip
Run the 13-inch swath for routine edging and touch-ups and save the 15-inch setting for overgrown lots. You will get noticeably more out of each battery, and the Easy Load head makes the occasional reload a 30-second job.
Warranty & Support
Tool Nut's Take
The Smart Way Into QUIK-LOK
The Milwaukee M18 QUIK-LOK Brushless 15-Inch String Trimmer Kit gives you gas-beating trimming power and a power head that grows into a full QUIK-LOK yard system.
- Who it's for: Homeowners, property managers, and landscape crews already on M18 who want a capable trimmer without gas.
- Why it stands out: Brushless power Milwaukee rates above 27cc gas, an adjustable 15-inch or 13-inch swath, and a 30-second line reload.
- Worth knowing: It is the Brushless line, not FUEL. The kit includes the 6.0Ah HIGH OUTPUT battery and charger, so it is ready to run.
Common Questions
- Is a battery included? Yes. The kit includes one M18 REDLITHIUM HIGH OUTPUT XC6.0 battery and an M18 and M12 Multi-Voltage Charger.
- Is this an M18 FUEL string trimmer? No. It uses Milwaukee's Brushless (non-FUEL) power head, model 3115-20. It still uses the QUIK-LOK coupler.
- What size trimmer line does it use? It accepts .080-inch or .095-inch line and ships with .080-inch line pre-wound.
- Can I use other attachments on this power head? Yes. The power head is compatible with all QUIK-LOK attachments.
- Does it need assembly? Yes. The bail handle bolts on with the two included bolts and Allen wrench.

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