Bosch 2 In. Starlock Carbide Grit Sanding Finger

A specialized attachment that actually earns its spot in the kit

Tight corners are where oscillating tools earn their keep, and that’s exactly where this carbide-grit sanding finger shines. I’ve been using this Bosch-made finger on a handful of fussy tasks—cleaning up cured epoxy squeeze-out inside cabinet carcasses, feathering paint in window sash corners, and nibbling away at grout where a full-size carbide blade would be overkill. It’s purpose-built for those moments when regular sandpaper or a larger oscillating accessory can’t reach or just burns up instantly.

Design and build

The finger is a tapered, 2-inch-wide carbide RIFF abrasive with a 1.5-inch immersion depth and roughly 4 inches overall length. The geometry feels right: enough width at the base for stability, narrowing to a point that genuinely gets into inside corners. The 0.125-inch thickness keeps it from chattering or flexing, even under a bit of side load.

The Starlock connection is tight and confidence-inspiring. The color-coded interface and laser-etched markings are small details, but they matter when you’ve got a pile of blades and abrasives in a job box. Being Swiss-made, the fit is exact—no rocking on the mount and no vague clicks when you seat it.

Setup and compatibility

Bosch calls this a Starlock Max interface, and it drops onto Starlock-ready tools with the usual one-step, tool-free action. On my Starlock tool, it’s a fast, glove-on swap. If you’re on an older OIS-style multi-tool, Bosch lists this as OIS compatible, but check your specific model; some tools need an adapter and not all non-Starlock tools will deliver the same high-torque, no-slip connection.

Once mounted, the finger sits close to the tool’s nose, which helps with control and keeps the oscillation path centered for precise work in narrow spaces.

In wood: detail sanding and epoxy cleanup

On wood, this is not a finishing accessory—it cuts more like a coarse carbide rasp or a 60-ish grit abrasive. I used it to remove cured structural epoxy fillets inside a plywood locker where no sanding block could reach. The finger skated over the high spots and pared them down quickly without loading up. Even with resin-rich squeeze-out, the carbide stayed clean enough that I never had to stop and pick it free. Dust extraction helps, but the open grit and vibration keep most of the debris from packing in.

Control is the key here. With a light touch and medium oscillation speed, you can feather back to clean wood without digging in. Press too hard and you’ll generate heat and leave deep scratch marks fast. I prefer to sneak up on the surface, then switch to conventional abrasives for the final passes. For trimming proud plugs or knocking down hardened glue lines at inside corners, it’s extremely efficient.

The pointed tip also lets you clean the very corner of face frames and door jambs where a rectangular sanding pad simply can’t reach. Because the abrasive is bonded to a rigid body, you can register the side of the finger against an edge to maintain a flat reference and avoid dish-outs.

In tile and masonry: small, controlled corrections

While it isn’t a dedicated grout saw, the carbide grit does just fine for controlled grout removal and for easing small high spots in thinset or mortar. I used it to clean a couple inches of stubborn grout behind a faucet escutcheon where a segmented blade wouldn’t fit. The finger shape made the difference; I could angle the point and work without scarring adjacent tile. Again, low speed, light pressure, and frequent checks are your friends—carbide will happily eat what you put in front of it.

If you’re doing whole-room grout removal, you’ll want a purpose-built accessory. But for patches, corners, and behind fixtures, this is faster and tidier than trying to force in a bigger blade.

Speed, control, and surface quality

Material removal is brisk for something this compact. Compared with hook-and-loop sanding pads, it’s dramatically more aggressive and much more resistant to clogging. The trade-off is a scratch pattern that requires follow-up if you’re aiming for a paint-ready or stain-ready surface. Think of it as a shaping and problem-solving tool rather than a finishing step.

Vibration is well controlled, in part because the finger’s body is stiff and compact. The Starlock interface helps; there’s no slop, so you don’t fight the accessory as it works. I ran it most of the time at middle speeds to keep heat down and preserve grit life.

Durability and maintenance

Carbide RIFF abrasives live or die by how they handle heat and contamination. After multiple sessions on cured epoxy and grout, the grit on my finger shows minimal wear and no bald spots. If you do gum it up with paint or resin, a quick scrape with a brass brush or a soak in a mild solvent clears the nibs. Unlike paper, this doesn’t “load and die”; it keeps cutting so long as you don’t blue it from excess heat.

The bond line between the abrasive and the body looks clean and even. I’ve seen cheaper fingers shed grit after a few minutes in mortar. That hasn’t happened here. Expect the finger to outlast a stack of regular sanding sheets by a wide margin.

Ergonomics and visibility

The tapered profile and compact footprint make sightlines better than with larger pads. You can see the point of contact and sneak right into the corner. Because the finger is relatively narrow, it also kicks up less dust than broader accessories, though it’s still worth pairing with vac extraction or working outside when possible.

One note: the edges are sharp and the grit is unforgiving. Glove up when swapping and keep the tool parked away from finished surfaces—just resting the finger on a painted sill can leave an unwanted kiss mark.

Limitations and best practices

• Not a finishing solution. Plan for follow-up sanding.
• Aggressive by design; use a light touch and moderate speed to avoid gouges.
• Compatibility can trip you up if you’re not on a Starlock platform; confirm fit if your tool is OIS-only.
• Flat, rigid face means it’s less effective on convex profiles; it excels on flat planes and inside corners.

Best practices that have paid off for me:
- Let the grit cut—don’t lean on it.
- Keep the accessory moving to prevent heat spots.
- Use the side of the finger as a reference against an edge when you need flatness.
- Clean the grit periodically to maintain cut speed.

Value

It costs more than disposable sandpaper fingers, but the cost-per-job pencils out quickly if you’re tackling cured adhesives, thick finishes, or small grout fixes. The speed of cut, the ability to reach into tight geometry, and the long life of the grit mean you spend more time working and less time swapping consumables.

The bottom line

As a problem-solver for tight spaces, this sanding finger earns a permanent slot in my oscillating kit. It’s fast, durable, and controllable once you respect its aggressiveness. The Starlock connection feels rock solid, the Swiss-made precision comes through in the fit and geometry, and the tapered profile genuinely reaches where other accessories can’t.

Recommendation: I recommend this sanding finger to anyone who routinely deals with cured glue or epoxy cleanup, interior corner prep, or small grout and mortar corrections. It’s not a finishing tool and it demands a light hand, but used properly, it saves time and delivers clean, controlled results in places that are otherwise a pain to reach. If you’re on a compatible Starlock tool (or have the right adapter for OIS), it’s a smart, long-lasting addition to the drawer.