Description:

Key Features

Fast Stock Removal The 9 amp motor spins at 12,000 RPM, so this grinder removes material quickly when you are cleaning welds, cutting metal, or knocking down edges. Built for Tight Spots The flathead gear case and low-profile design help the small angle grinder get into places where a bulkier grinder gets in its own way. Quick Wheel Changes A quick-change wheel release lets you swap accessories without reaching for a wrench, which saves time when the job keeps changing.

Overview

The DeWALT DWE4120FN 4-1/2-In. - 5-In. Flathead Paddle Switch Small Angle Grinder With No Lock-On is a corded metalworking and grinding tool built for fast material removal in cramped work areas. This is a small angle grinder designed for grinding, cutting, and surface prep in tight spaces. Model Number: DWE4120FN. If you need a grinder that can reach between rails, against framing members, or into fabrication work where head clearance matters, this is the whole point of this tool.

The motor is rated at 9 amps and 12,000 RPM, which gives this grinder the speed needed for aggressive grinding and cut-off work on steel and other common jobsite metals. In practical use, that means less waiting on the wheel and more steady removal when you are dressing welds, trimming angle iron, or cleaning up tubing. DeWALT also calls out higher overload protection and low operating temperatures from the high-efficiency motor, which matters when the grinder is being pushed through repeated cuts instead of light touch-up work.

What separates this model from a standard compact grinder is the flathead, low-profile gear case. That housing design is there for access. It helps the tool fit where a taller gear case would block the wheel before you can finish the pass. On railings, structural steel, pipe, and welded corners, that extra clearance is not a small detail. It is the difference between finishing the cut with one tool or stopping to change tools or approach angle.

The body shape is slim and ergonomic, which makes a difference on longer grinding sessions. A grinder that is easier to wrap your hand around gives you better control and less fatigue, especially when you are working one-handed to position the tool while the other hand steadies material or supports your stance. The paddle switch layout also suits control-focused work, and the no lock-on design is a good fit for users who want the tool to stop as soon as they release the switch.

On the job, quick setup changes matter almost as much as power. This model uses a quick-change wheel release for tool-free wheel removal, so switching from one accessory to another is faster than dealing with a wrench every time. The 2-position removable side handle also helps you tune the setup for the cut, the grind angle, or the direction of approach. That is useful when you are moving between edge grinding, flush work, and general metal cleanup.

The DeWALT DWE4120FN 4-1/2-In. - 5-In. Flathead Paddle Switch Small Angle Grinder With No Lock-On is a corded platform tool, so you are getting continuous AC/DC power without battery management, charge time, or runtime limits. It accepts a wide range of 4-1/2 inch accessories and uses a 5/8 inch - 11 spindle thread, which keeps replacement wheels and common grinder accessories easy to source. If your work is mostly at the bench, in the shop, or anywhere power is available, that compatibility and constant output make sense.

This grinder is best suited for metalworkers, welders, fabricators, maintenance crews, contractors, and serious DIY users who need compact access more than they need cordless freedom. If most of your grinder work happens in open space, a standard head design may be enough. If you regularly work around railings, channels, pipe, structural shapes, or other tight metal layouts, this flathead design earns its keep fast.

Reach Into Tight Metalwork

The flathead housing is built for the kind of spots where a regular grinder head hits the work before the wheel can do its job. That makes this a strong choice for railing work, corners, and close-clearance fabrication.

• Low-profile, jam-pot gear case helps the tool fit into tight spaces
• 4-1/2 inch to 5 inch wheel capacity covers common grinding and cut-off tasks

Keep Material Moving

This grinder has the speed for real stock removal, not just light cleanup. When you are knocking down welds, blending edges, or making cut-off passes, the motor output helps the wheel stay productive.

• 9 amp AC/DC motor is designed for faster material removal
• 12,000 RPM top speed supports grinding, cutting, and metal prep work

Set It Up for Control

A grinder is only useful if you can hold it where you need it. The slim body and removable side handle make it easier to stay comfortable and keep the wheel where you want it, especially during repeated passes.

• Slim ergonomic body design is built for extended use applications
• 2-position removable side handle adds comfort and directional control

Change Accessories Without the Extra Step

When the work shifts from grinding to cut-off or surface cleanup, faster wheel changes save time. The quick-change wheel release cuts down the hassle of swapping accessories between tasks.

• Quick-change wheel release allows tool-free wheel removal
• 5/8 inch - 11 spindle thread supports common grinder accessories

What's in the Box

• (1) Grinder
• (1) Side Handle
• (1) Hex Key
• (1) Inner and Outer Flange
• (1) 5 in. Type 27 Guard

Key Specifications

Compatibility

Wheel Size Accepts 4-1/2 in. to 5 in. grinder accessories. Spindle Interface Uses a 5/8 in. - 11 spindle thread for common angle grinder wheels and accessories. Power Input Runs on corded AC/DC power for continuous operation where outlet power is available.

Built For

Metalworking Welding Cleanup Fabrication Construction Maintenance and Repair Tight-Space Grinding Cut-Off Work Surface Prep

Pro Tip

When you are working between rails or up against tubing, rotate your approach so the flathead gear case stays parallel to the obstruction, then move the side handle to the position that gives your wrist the straightest line. That setup is where this grinder separates itself from a standard head design.

Warranty & Support

3 Year Limited Warranty, 1 Year Free Service, 90 Day Satisfaction Guaranteed.

Tool Nut's Take

Tool Nut's Take

DeWALT DWE4120FN Small Angle Grinder for the Spots That Usually Fight Back

The big win with this grinder is simple: it reaches where a regular grinder head starts getting clumsy.

• Who it's for: Fabricators, welders, metal trades, and contractors who spend real time working around railings, tube, angle iron, and other tight layouts.
• Why it stands out: The flathead gear case, 9 amp motor, and quick-change wheel release make it more useful than a basic compact grinder when access and speed both matter.
• Worth knowing: This is a corded, no lock-on grinder, so it is best for users who want constant power and switch-controlled operation rather than battery freedom.

Common Questions

• Is this a corded or cordless grinder? It is a corded grinder and runs on AC/DC power.
• What size accessories does it accept? It accepts 4-1/2 inch to 5 inch accessories and uses a 5/8 inch - 11 spindle thread.
• Does this grinder have variable speed? No. The listed specification shows no variable speed or electronic speed control.
• What is the top speed? The motor is rated for 12,000 RPM no-load speed.