Bosch 7-1/4 In. 4 Tooth Edge Diamond-Impregnated Carbide-Tipped Saw Blade

Why I reached for this blade

Fiber-cement siding and backer board are unforgiving on saw blades. They’re abrasive, dusty, and quick to dull traditional carbide. After a couple of projects left my general-purpose blades scorched and useless, I switched to the Bosch fiber-cement blade—a 7-1/4 in., 4-tooth, diamond-impregnated carbide-tipped option designed specifically for this material. I put it to work on HardiePlank lap siding and a handful of cement backer board cuts, using both a sidewinder and a worm-drive saw. The short version: it cuts fast, stays sharp noticeably longer than standard carbide, and helps keep dust in check better than I expected from such an aggressive tooth count.

Setup and compatibility

The blade runs a standard 7-1/4 in. diameter with a 5/8 in. diamond knockout arbor, so it drops onto most portable circular saws without drama. I used it primarily on a 15A sidewinder (6,000+ RPM) and a worm drive (lower RPM, higher torque). The blade’s 7,900 max RPM rating covers either style. No shims, no odd spacing. The plate measures 0.07 in. thick with a 0.102 in. kerf, a reasonable “thin-kerf” that reduces load on the motor without feeling fragile or prone to deflection.

Tooth geometry and design

This blade is all about controlled aggression. Four flat-top grind (FTG) teeth, a modest 10° hook angle, and deep gullets combine to move through cementitious material quickly while letting the saw breathe. FTG teeth act like tiny chisels; they don’t “slice” so much as they punch and clear. The deep gullets do a lot of the heavy lifting by evacuating pulverized cement before it packs the cut. The anti-friction coating (Bosch calls it a SpeedCoat) helps the plate shed dust and run cooler.

The tips are diamond-impregnated carbide—not full polycrystalline diamond (PCD) like you’ll find on premium production blades, but a step above conventional carbide. In practice, it’s a smart middle ground for remodelers and small crews who need more life than a basic cement blade without paying top-tier PCD prices.

Cutting performance

On 5/16 in. lap siding, the Bosch blade fed smoothly with a steady, moderate push. The low tooth count means you’re not waiting on fine teeth to nibble along; the blade bites, ejects dust, and keeps moving. On a sidewinder, the thin kerf translated to fewer bog-down moments when I hit knots in underlying sheathing or had to power through a slightly awkward stance. The worm drive delivered a touch more authority at the start of the cut, but both saws felt at home with this blade.

Crosscuts were clean enough for exposed ends, especially on pre-primed boards. Rips along factory edges were surprisingly tidy for a four-tooth profile. If you demand paint-grade edges on show faces, a quick pass with 120-grit or a fiber-cement sanding block took off the minimal fuzz that remained.

Backer board is a different story. I still prefer score-and-snap for straight cuts indoors to minimize dust, but when I needed notches or curves, this blade handled them without chipping out the cement face. Keep feed pressure even and let the gullets clear; forcing the cut will just pack dust into the kerf and increase heat.

Dust and heat management

No blade eliminates silica dust, but this one does a better job than many 6–8 tooth cement blades I’ve used. The deep gullets and coating help keep dust moving down and out of the cut instead of atomizing it. Cutting outside, with the wind at my back and a vac attached to a shroud, the airborne plume was meaningfully reduced compared to a generic cement blade I had on hand.

After longer sessions—think 20–30 consecutive cuts—the plate was warm but not discolored, and I didn’t notice the sticky drag that shows up when a blade’s coating wears quickly. The 0.102 in. kerf also reduces the amount of material turned into dust by a noticeable margin over thicker plates.

Important note: this is still silica dust. Wear a proper respirator, use a shroud and HEPA vac, and cut outdoors whenever possible. The blade helps, but it’s not a substitute for safe practices.

Edge quality and control

A four-tooth blade can be a handful on wood; on fiber cement, the slower feed and higher resistance make it feel controlled and predictable. The 10° hook angle keeps the blade from self-feeding, which I appreciated when trimming narrow rips or cutting short offcuts that can vibrate. I saw minimal blowout on the exit side when I supported the workpiece properly. If you’re cutting finished siding that will be butted into trim, that clean exit saves time.

For miters on corner boards, I had acceptable results at 45°, but I slowed my feed slightly and made sure the work was well supported to avoid any edge crumble on the acute side of the cut.

Durability and blade life

Here’s where the diamond-impregnated carbide earns its keep. After a siding run with a little over a hundred cuts—mix of crosscuts, a handful of rips, and some angle cuts—the teeth still looked sharp under a loupe, and the cut quality hadn’t fallen off. With a standard carbide cement blade, I usually notice diminishing performance well before that. Is it going to match a true PCD blade for life? No. But for remodel-scale jobs or small to midsize installations, the lifespan-to-cost ratio is compelling.

I also appreciated that the plate stayed flat. Cement dust is brutal; if a blade starts to heat and wander, you’ll see it fast. This one tracked straight with no telltale chirping or burnished kerf walls.

What I liked

• Fast, controlled cutting with a modest feed force
• Respectable dust management for a 4-tooth profile
• Edge quality good enough for exposed ends with minimal touch-up
• Noticeably longer life than standard carbide in fiber cement
• Plays nicely with both sidewinders and worm drives
• Thin kerf reduces load on 15A saws

Where it falls short

• Four-tooth geometry isn’t about ultra-smooth finishes; expect a utility edge without quick sanding
• Not a replacement for PCD longevity on high-volume crews
• Kerf is thin, but not the thinnest—track-saw-level precision isn’t the goal here
• Still generates hazardous dust; you must have a shroud/vac or work outside with PPE

Tips for best results

• Cut with the good face down on a portable saw to reduce top-surface fuzz.
• Support the work fully—especially near the exit—to prevent edge crumble.
• Use a dedicated fiber-cement saw shroud and HEPA vac; align the vac port with the gullet flow.
• Keep a light, steady feed. If you feel the blade slow, back off slightly and let the gullets clear.
• Mark cuts generously; remember a 0.102 in. kerf and keep your reveals consistent on lap siding.

Who it’s for

If you’re a remodeler, siding contractor on smaller runs, or a serious DIYer tackling a fiber-cement project, this blade hits a sweet spot. You get much better life than standard carbide and faster, cleaner cuts than bargain cement blades, without jumping to the price tier of full PCD. Production siding crews who live on fiber cement every day will still see value in PCD for maximum longevity, but I’d keep this Bosch blade in the kit for mixed-material days or punch-list work.

Final recommendation

I recommend the Bosch fiber-cement blade. It combines smart geometry (FTG, 4 teeth, deep gullets) with a durable, diamond-impregnated carbide tip that holds up to abrasive materials better than standard carbide. In use, it cut quickly, stayed cool, produced cleaner edges than I expected from a low tooth count, and noticeably reduced airborne dust when paired with a shroud and vac. For the majority of siding and backer board tasks on portable saws, it’s a reliable, cost-effective choice that balances speed, control, and longevity. If your work is exclusively high-volume fiber cement, step up to PCD for ultimate life; otherwise, this blade is an easy pick for quality results without fuss.