Mirka FBS-B 10 12V 3/8-in. x 13-in. Cordless File Belt Sander 5.0Ah Kit with Charger (MUS-FBS10)

The Mirka FBS-B 10 .375″ x 13″ Cordless File Belt Sander with Charger and Batteries is a cordless file belt sander built for body repair, weld cleanup, paint removal, and restoration work. This is a file belt sander designed for spot weld grinding, weld seam grinding, and tight-access metal sanding. Model MUS-FBS10 includes the tool, two 5.0Ah max 12V Li-Ion batteries, and a charger, so it is ready for the shop right out of the box.

Where this tool earns its keep is access. A narrow .375 inch by 13 inch belt lets you work into seams, edges, and repair zones that are hard to reach with a larger belt sander or grinder. For auto body techs and restoration guys, that means better control around spot welds, welded joints, and rusted sections where you need removal speed without giving up precision.

Mirka uses a brushless electric motor here, and that matters for more than just spec-sheet talk. A brushless setup gives you long service life, strong power delivery, and a smoother feel under load. Mirka also calls out quiet operation and fast, aggressive material removal, which is exactly what you want when the job is repetitive and you are moving from weld to weld all day.

The cordless design is a major upgrade over air-powered file sanders if you are tired of dragging hoses around the vehicle or tying up compressor capacity. This sander is built for workshops and job sites where compressed air is impractical, and it gives you freedom to reach awkward repair areas without fighting hose management. In real use, that means less setup hassle and easier movement around panels, pillars, and inside corners.

Control is another strong point. The Mirka FBS-B 10 uses speed setting buttons along with a stepless trigger, so you can creep into delicate work or lean into faster stock removal as needed. That kind of control matters when you are switching between knocking down a seam and refining the surface before the next finishing step. Mirka also includes a belt position adjustment knob, which helps keep the belt tracking where it should instead of wasting time on fussy alignment.

For day-long use, Mirka kept the tool light, balanced, and ergonomic. The bare tool weighs only 1.5 lbs., and it comes in at just over two pounds with a battery installed, depending on battery choice. Add in the rubberized handle and you get a tool that is easier to manage in difficult positions, especially when you are working one-handed or reaching into areas where a heavier grinder would wear you out fast.

This version is the kit, not the bare tool. MUS-FBS10 includes two 5.0Ah batteries and a charger. Mirka also notes that the same batteries are used across other Mirka cordless tools, including cordless sanders, polishers, and the Mirka ANGOS ARG-B cordless grinder. If you are already in that system, battery sharing is a real advantage. If not, this kit is the easier starting point because you are not buying the tool and then chasing power separately.

Mirka added job-focused details that make sense for metalworking and repair environments, including an integrated LED light, a spark protection flap, open belt protection for quick abrasive belt changes, and Bluetooth connectivity through the myMirka app. The app-based features include vibration measurement, RPM range management, and belt speed monitoring. Bottom line: this is a specialized cordless belt sander for pros who need reach, control, and mobility for metal repair work, not a generic sanding tool trying to do everything.

Mirka FBS-B 10 Cordless File Belt Sander is built for metal repair guys who need reach, control, and mobility

This is the kind of specialized tool that saves time because it gets into places a regular grinder or wider sander simply cannot.

• Who it’s for: Auto body techs, restoration shops, and metal fabrication users doing spot weld removal, seam cleanup, and tight-access sanding.
• Why it stands out: You get a brushless cordless setup, a narrow 3/8 in. x 13 in. belt format, app connectivity, and a full kit with two 5.0Ah batteries and charger.
• Worth knowing: This is a purpose-built repair tool, not a general bench sander. If your work lives in seams, edges, and repair patches, that is exactly why it makes sense.

• Is this a corded or cordless belt sander? It is a cordless file belt sander powered by Mirka Li-Ion batteries.
• What kind of work is it designed for? It is designed for body repairs, spot weld grinding, weld seam grinding, vehicle manufacturing, restoration work, and paint removal.
• Does it use a brushless motor? Yes. Mirka specifies a brushless electric motor for long life and strong performance.
• Can it connect to an app? Yes. Bluetooth connectivity works with the myMirka app for vibration measurement, RPM range management, and belt speed monitoring.