Milwaukee Multi-Tool Blade Compatibility
Milwaukee took a different approach to multi-tool blade compatibility than most competitors. Rather than adopting Starlock or sticking with universal-fit, they developed their own OPEN-LOK system — but crucially, every Milwaukee multi-tool ships with a universal adapter that accepts most other brands’ blades. This makes Milwaukee one of the most flexible platforms for blade choice on the market.
Quick Answer
Milwaukee multi-tools use the proprietary OPEN-LOK system. They also accept universal-fit blades, but Starlock and OIS blades will NOT fit.
Milwaukee Multi-Tool Models and Blade Systems
| Model | Type | Blade System | Accepts |
|---|---|---|---|
| M18 FMT-0 (2836-20) | Cordless 18V FUEL | OPEN-LOK | OPEN-LOK blades + most other blades via included adapter |
| M18 FMT-522X | Cordless 18V FUEL (kit) | OPEN-LOK | OPEN-LOK blades + most other blades via included adapter |
| M12 FMT-0 (2526-20) | Cordless 12V FUEL | OPEN-LOK | OPEN-LOK blades + most other blades via included adapter |
| M12 FMT-422X | Cordless 12V FUEL (kit) | OPEN-LOK | OPEN-LOK blades + most other blades via included adapter |
How OPEN-LOK Works
OPEN-LOK is Milwaukee’s proprietary blade interface designed for maximum rigidity and fast tool-free changes. Blades lock in with a secure three-point contact system that minimises vibration and blade flex during operation.
The key selling point is the included universal adapter — a mounting plate that ships with every M18 FMT and M12 FMT tool. With this adapter installed, your Milwaukee multi-tool can accept virtually any competitor blade: Starlock, OIS, universal-fit, and most proprietary formats. This gives you the widest possible blade selection of any platform.
What Blades Work With Milwaukee?
Natively (OPEN-LOK): Milwaukee’s own OPEN-LOK blades provide the best performance on Milwaukee tools, with minimal vibration and maximum blade stability.
Via adapter: Starlock blades (Bosch, Fein, Makita), OIS blades, universal-fit blades from Ryobi, Dremel, Hikoki, and most third-party brands. The adapter effectively makes the Milwaukee platform compatible with nearly everything on the market.
Exception: DeWalt proprietary horseshoe blades may not fit the universal adapter due to their unique mounting shape. Check specific adapter documentation before purchasing.
Recommended Milwaukee Multi-Tool Blades
| Blade | Type | Best For | Link |
|---|---|---|---|
| Milwaukee OPEN-LOK Wood Blade | Bi-metal plunge cut | General wood cutting | View on Amazon |
| Milwaukee OPEN-LOK Titanium Enhanced Metal Blade | Metal cutting | Sheet metal, copper pipe | View on Amazon |
| Milwaukee OPEN-LOK Carbide Teeth Metal Blade | Carbide-tipped | Hard metals, stainless steel, bolts | View on Amazon |
| Milwaukee OPEN-LOK Multi-Tool Kit (6-piece) | Mixed set | All-round professional kit | View on Amazon |
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Common Questions
Do I need to buy the universal adapter separately?
No. The universal adapter is included with every M18 FMT and M12 FMT multi-tool. It’s in the box alongside the tool — you don’t need to purchase it as a separate accessory.
Is performance worse with the adapter?
There is a marginal difference. OPEN-LOK blades provide the tightest, most vibration-free connection. Using the adapter with third-party blades may introduce slightly more play, but for most practical purposes the difference is negligible. Many tradespeople use the adapter daily with Bosch Starlock blades and report excellent results.
Should I buy Milwaukee OPEN-LOK or Bosch Starlock blades for my M18 FMT?
For the best performance, use OPEN-LOK blades natively. But Bosch and Fein have a wider range of specialist Starlock blades (especially for grout, tile, and sanding). The ideal approach is to keep OPEN-LOK blades for your most-used tasks and use the adapter with specialist Starlock blades when needed.