The Milwaukee 3450-20 M12 Subcompact Brushless 1/4 Hex Impact Driver is a cordless fastening tool built for compact size, fast driving speed, and everyday carry convenience. This is a 1/4 inch hex impact driver designed for driving screws, lag bolts, and other fasteners in tight spaces. Model 3450-20 is the bare tool version, so it is aimed at users already on the Milwaukee M12 platform who want a lighter, shorter driver without stepping down to a weak tool.

What matters here is the size-to-output balance. Milwaukee rates this subcompact impact driver at up to 1,100 in-lbs of torque, up to 3,000 RPM, and up to 4,100 IPM. On the job, that means quicker driving in common fastening work without the bulk of a full-size impact driver. If you spend time inside cabinets, electrical boxes, mechanical rooms, or finished interior spaces, the short head length helps you stay on the fastener instead of fighting for clearance.

The physical dimensions are the real story. At 4.3 inches long and 2.0 inches wide, this tool is built to reach spots that usually force you to switch tools or change your angle. That is useful for installers, remodelers, cabinet work, punch-out, and service trades where access is often the problem, not raw power. Milwaukee also keeps the bare tool weight down to 1.3 lb, with a listed weight of 1.7 lb with battery, so it is easier to use overhead and easier to keep on your belt through a long day.

Milwaukee backs the compact footprint with details that matter for durability and day-to-day use. The internal metal gearcase adds strength where a small impact driver takes repeated hits. The 1/4 inch hex collet is built for standard impact-rated bits, and the variable speed trigger gives you better control when you are starting small fasteners or working with delicate hardware. There is also an LED light to help in dim cabinets and utility spaces, plus an on-tool battery fuel gauge so you are not guessing at runtime.

This driver uses a brushless motor, which is a big part of why it can stay compact while still putting out real fastening performance. It also uses Milwaukee REDLINK Intelligence, which is there to help protect the tool and battery from overload and heat in tougher applications. That matters if you are using it beyond light assembly work and want a compact tool that still holds up when the pace picks up.

Platform compatibility is straightforward. The Milwaukee 3450-20 M12 Subcompact Brushless 1/4 Hex Impact Driver is part of the Milwaukee M12 battery system and works with M12 REDLITHIUM batteries. It is also listed as compatible with Milwaukee accessory bit holder 49-16-3697. If you are already invested in M12, this is an easy add because it gives you a true compact fastening option without adding another battery line to the truck.

Who should buy it? Pros who need a compact cordless impact driver for service work, finish work, cabinet installs, electrical, HVAC, and general remodeling will get the most out of it. Serious DIY users will also appreciate how manageable it is for furniture assembly, deck repairs, hardware installs, and home projects where a larger impact driver feels clumsy. If your work is mostly long structural fasteners all day, you may still want a larger high-output driver. But if access, carry comfort, and quick fastening are higher on the list, this one makes a lot of sense.

Milwaukee 3450-20 M12 Subcompact Brushless 1/4 Hex Impact Driver for the guy who is always short on space

This is one of those tools that earns its keep by being easy to carry, easy to fit, and still strong enough that you do not feel like you settled.

• Who it's for: Anyone doing install work, service calls, cabinet work, punch-list tasks, or everyday fastening on the M12 platform.
• Why it stands out: The 4.3 inch length, 1.3 lb bare tool weight, and 1,100 in-lbs of torque are a strong combo for a true subcompact impact driver.
• Worth knowing: This is the bare tool only, so if you are not already running M12 batteries and a charger, add those to the cart.

• Is this a brushless impact driver? Yes. It uses a brushless motor.
• What battery platform does it use? It is part of the Milwaukee M12 system and works with M12 batteries.
• How much torque does it make? Milwaukee lists up to 1,100 in-lbs of torque.
• How fast does it run? The listed no-load speed is 0 to 3,000 RPM with an impact rate of 0 to 4,100 IPM.
• Does it have ONE-KEY? No. This model is not ONE-KEY enabled.