Bosch 1-1/4 in StarlockMax Oscillating Multi-Tool Carbide Plunge Cut Blade

Why I reached for this blade

Tight, awkward cuts are where an oscillating tool shines, and that’s exactly the niche where the Bosch StarlockMax carbide plunge blade earns its keep. I used it for jobs I usually dread—cutting old galvanized pipe inside a crawlspace, notching around masonry, and making clean square openings in fiber-cement siding—where a recip saw, grinder, or hacksaw would be messy, risky, or simply impossible to maneuver.

Mounting and compatibility

This is a StarlockMax blade. That matters. It snaps onto a StarlockMax oscillating multi-tool via a three-dimensional interface that locks solidly with no screws or clamping flange. The fit is rigid and transfers torque really well, with noticeably less vibration than bolt-on blades. The tradeoff: it does not fit older OIS bolt-on tools or even standard Starlock/StarlockPlus tools. If your tool isn’t specifically StarlockMax compatible, this blade won’t mount. That may be a deal-breaker for some, but if you’re already in the Starlock ecosystem, the security and convenience of the mount are big advantages.

Build and design

The blade is 1-1/4 inches wide with a roughly 1.5-inch effective plunge depth and a long 4-inch body that adds reach without feeling whippy. The plate is thicker than many oscillating blades—0.125 inch—which I appreciated when tracking straight in hard materials. It resists deflection, which translates to cleaner, more predictable cuts, especially during aggressive plunges.

The carbide teeth are the star. They’re designed for abrasive and metallic materials: ferrous pipe, nails, cement board, drywall, and even small tile notches. The body is laser-etched and clearly marked, and the Starlock interface is color-coded, which sounds trivial until you’re fishing in a pouch of mixed blades; it genuinely speeds up the right choice.

Swiss manufacturing shows in the clean tooth brazing and consistent flatness. Everything about the blade feels purpose-built and durable.

Cutting metal: pipe, rebar, and embedded fasteners

Steel pipe in a cramped cavity was my first test. I had to remove a section of old 1/2-inch galvanized water line with only a few inches of swing. The blade didn’t scream through it the way a grinder would, but it bit cleanly and stayed on line without skating around. Plunging to about halfway, then working around the circumference, I could complete the cut in a controlled way with minimal risk to surrounding joists. The lack of kick and the stable Starlock connection made it much calmer than using a cutoff wheel in tight quarters.

I also took on a short length of #3/#4 rebar. With steady pressure and mid-to-high oscillation speed, the blade got through in under half a minute. Expect sparks near the end of the cut as the teeth work hard—normal for carbide meeting steel—but manage heat by easing off occasionally. After a couple of heavy metal cuts, I could see the tooth tips beginning to dull, as you’d expect, but the blade had plenty of life left for lighter duty like nails, screws, and thin conduit.

For wood with nails (think trim with hidden brads or subfloor screw shanks), this blade chews straight through without drama. It’s a confidence booster when you don’t want to swap blades mid-cut or risk chipping a wood-only edge on metal.

Cement board, siding, and tile-adjacent tasks

Where this blade surprised me most was in fiber cement and cement board. I used it to square up openings for exterior receptacles and hose bibbs in cement siding. Unlike a grinder, which throws dust everywhere and struggles to nibble tight corners, the oscillating blade produced a more controlled kerf and kept dust far more localized. Hooked to a vac, it was a manageable amount of debris.

For cement board around a tub alcove, plunging out notches for fixtures was almost surgical. It’s not fast compared to a circular saw with a PCD blade, but it’s tidy and accurate in close quarters.

As for ceramic tile, this is a “use sparingly” tool. It can nick a small notch or clean up a corner where a diamond blade couldn’t reach, but I wouldn’t use it for long scores or full tile cuts. Carbide will wear quickly on glazed tile; pick your spots carefully.

Wood and composites

On clean wood, the blade will cut, but it’s not the right choice for finish work. The thick kerf and carbide tooth geometry generate heat and can scorch edges, especially in dense lumber or OSB. If I needed to plunge a mortise in softwood or flush a jamb for flooring, I swapped to a wood-specific blade for speed and cleaner edges. The carbide blade’s wood cutting capability is more of a “get through it even if there’s metal” safety net than a primary solution.

Control, accuracy, and vibration

Two things stand out in use: control and calm. The StarlockMax interface really does reduce slop. On plunge cuts into hard materials, the lack of chatter and wandering helped keep the cut right where I wanted it. I also appreciated being able to clock the blade at different angles on the tool—handy when the tool body doesn’t align with the cut line in a cabinet or tight stud bay.

Vibration is notably lower than with bolt-on blades, which matters on longer cuts in steel or cement board. Less buzz equals less fatigue and better tracking.

Durability and value

Bosch claims significantly longer life than bi-metal blades; in practice, that held true for me in abrasive materials. In fiber-cement tasks, one blade carried me through a healthy batch of openings before I noticed any slowdown. In ferrous metal, no magic: carbide is still consumable, and heavy steel will wear it, but it outlasted bi-metal alternatives I’ve used for the same work.

It’s a premium-priced, single-pack blade, and that cost makes sense only if you actually need what it does: controlled metal and abrasive cuts in spaces other tools can’t reach. If you’re mostly cutting wood or plastic, a cheaper bi-metal or wood blade is more cost-effective. If you’re cutting a lot of thick steel in open areas, a grinder or recip saw will be faster and cheaper per cut. This blade is about control and access first, speed second.

Tips for best results

• Check compatibility: StarlockMax only. It won’t fit most non-Starlock tools.
• Let the carbide do the work: moderate pressure, steady speed. For steel, use mid-to-high speed and short breaks to manage heat.
• Avoid side-loading: keep the blade aligned with the cut to protect the brazed carbide teeth.
• Cool-down cycles: a few seconds off the cut between passes extends life.
• Dust management: with cement board or siding, pair with a vac and score corners before completing cutouts.
• Use the right blade for wood finish cuts: swap to a wood blade if you want clean edges and speed.

Who it’s for

• Pros and serious DIYers already on a StarlockMax platform.
• Plumbers, electricians, and remodelers who routinely face metal and abrasive materials in tight, finished spaces.
• Anyone needing precise plunge cuts near delicate surfaces where a grinder or recip saw would be risky or messy.

If you rarely encounter metal or cement board, or your oscillating tool isn’t StarlockMax, you’ll get better value elsewhere.

Recommendation

I recommend the Bosch StarlockMax carbide plunge blade to users who need controlled, accurate cutting in metal and abrasive materials where access is limited. The secure StarlockMax mount, thick and stable blade body, and carbide teeth deliver calm, predictable plunges that other blades struggle to match. It’s not the fastest option in open-air metal cutting, and it’s overkill for clean wood, but in the situations oscillating tools are made for—tight, careful cuts with mixed materials—this blade is exactly the right tool. If you own a StarlockMax multi-tool and regularly work around pipe, nails, cement board, or fiber cement siding, the performance and durability justify the premium. If you’re on a different mount system or mostly cut wood, skip it and save the cash.