Bosch 11 Piece Diamond Hole Saw Set

Why this diamond hole saw kit earned a spot in my tile kit

I’ve tried most of the common approaches to cutting clean holes in tile and stone, and very few strike the right balance of speed, control, and edge quality. This Bosch hole saw kit gets closer than most. After putting it to work on a kitchen backsplash in porcelain, several floor tiles, and a couple of shower wall penetrations, I came away impressed by how predictable the cuts were and how little drama there was in starting holes. It’s not the cheapest route, and it won’t be the perfect size for every job, but as a core kit for tile holes, it’s a strong choice.

Setup and first impressions

The kit arrives in a sturdy plastic case with clearly labeled sizes and a dedicated slot for the mandrel and AutoStart pilot. The lineup covers a mix of small and large diameters: 1/4, 5/16, 3/8, 5/8, 1, 1-3/8, 2, 2-1/4, and 2-1/2 inches. That’s nine hole saws, plus the mandrel and the AutoStart bit, for eleven pieces total. The range covers a lot of what I encounter—anchors, valve stems, shower arm, and waste/vent openings—though there are times you’ll want a 1-1/2 inch bit or other in-between sizes that aren’t included.

Bosch’s vacuum-brazed diamond rims and segmented cutting edge are the headline features. The finish on the rims is consistent, with clean segment gaps for slurry evacuation. The mandrel is a snap-in style that locks the cups securely and allows quick swaps. The AutoStart pilot bit sits in front on a spring-loaded shaft; it extends to help you begin the hole, then retracts as the cup engages.

Starting holes: where this kit stands out

Getting a diamond cup to bite on porcelain without skating is often the make-or-break moment. The AutoStart system works well. On polished porcelain wall tile, the pilot point gave me a confident start without having to tape the surface or build a jig. The pilot contacts the surface, creates a shallow “dimple,” and the moment the rim begins to grind, the pilot retracts—so you’re not trying to drill a deep pilot hole in tile, which is a recipe for cracks.

Two caveats based on my use:
- On very hard, textured porcelain, I still prefer to start at a slight angle for the first second and then square up. The AutoStart helps either way, but technique still matters.
- On delicate stone or glassy finishes, I keep the pressure light and the speed low so the pilot doesn’t chip the glaze. A couple of slow rotations to score the surface before going to full rim contact works well.

Cutting performance and heat control

These are designed for wet cutting, and with water on the cut, they track straight and cut fast. The segmented rim clears slurry efficiently, which keeps the diamonds cutting instead of glazing over. I use three wetting methods depending on the situation:
- A spray bottle for vertical surfaces
- A water dam made from putty around the layout on flat surfaces
- A sponge pressed just ahead of the cut

At a deliberately slow speed on a cordless drill (no hammer action) with medium pressure, I got clean holes with minimal edge spall. On a 3/8-inch floor tile, the 1-3/8-inch cup cut through in well under a minute without overheating. The 2-1/2-inch size naturally takes longer; pecking the cut (in and out to clear slurry) and keeping water flowing kept the rim from discoloring and maintained speed.

If you’ve only used bargain, electroplated diamond cups, the difference shows up after a few holes. Vacuum-brazed grit tends to last longer before the cutting slows, and I noticed less “screaming” when the rim hit hard inclusions in porcelain. After several holes at 1-3/8 and two at 2-1/2 inches in porcelain, the rim still cut cleanly. As with all diamond cups, pressure and heat are the killers—let the diamonds work, and they hold up.

Accuracy and edge quality

The edge finish is one of the stronger points. Backing the tile with scrap foam board or a sacrificial tile and keeping the cut wet left me with a crisp rim and only a hairline of micro-chipping on the exit side. For exposed holes (say, a shower arm that won’t get a trim escutcheon), I started from the visible face and tidied the rim with a quick pass, which was enough for a clean look. On thicker materials or where the 1-inch maximum cutting depth becomes a limit, drilling halfway from both faces keeps blowout in check—but alignment must be dead on.

Limits and tradeoffs

• Maximum cutting depth: The 1-inch max depth is the ceiling. On 3/4-inch porcelain with a cement backer board underneath, you’ll do fine. On some countertops with thicker buildup, you’re either drilling both sides or stepping to a longer cup.
• Size coverage: The selection hits many common plumbing sizes, but it isn’t exhaustive. If you frequently need a size that’s not here, plan to add an individual cup.
• Wet cutting requirement: The kit excels wet. Dry attempts on porcelain will run hot, glaze the rim, and increase chipping. If you can’t introduce water safely (think overhead cuts near live electrical), you’ll need a workaround or a different product designed for dry use.

Tips for best results

• Skip hammer mode and high speeds. Slow-medium RPM, steady pressure.
• Start accurately: let the AutoStart pilot touch first, or start at a slight angle to score, then roll upright.
• Keep it wet. A spray bottle is the easiest insurance policy against heat and glaze.
• Use pecking cuts on large diameters to clear slurry and prevent core-binding.
• Back the work. A sacrificial layer reduces breakout on the exit side.
• Let off when the core plug loosens; don’t wrench it out mid-cut. Easing off avoids sudden chip-outs.

Build, ergonomics, and storage

The mandrel’s engagement is positive, and the cups seat without play. I appreciated the quick removal for clearing core plugs—press, twist, pop, done. The case is compact enough to live in a job bag and actually keeps the set organized, which matters when you’re fishing for a size mid-job with wet hands. I wouldn’t call the case heavy-duty, but it’s rigid enough to protect the rims and latch reliably.

Value proposition

This is a professional-leaning kit. If you only need one or two holes for a single project, a single cup in the right size might be a smarter buy. If you regularly cut holes in porcelain or ceramic—and especially if you’ve been frustrated by bits that dull after one or two cuts—the durability and ease of starting holes make this package good value over time. Fewer blown tiles and cleaner holes are real time-savers.

Who it’s best for

• Tile installers and remodelers who need a dependable range of sizes with clean starts and consistent cuts.
• Serious DIYers taking on bathrooms or kitchens with porcelain tile who want predictable results and fewer cracked pieces.
• Maintenance trades who encounter a mix of small and large penetrations and can keep water on the cut.

If you work extensively in thick stone countertops or need dry cutting, this isn’t the ideal fit.

The bottom line

This Bosch set impressed me with its controlled starts, steady cutting speed, and edge quality on porcelain and ceramic. The vacuum-brazed rims and segmented design do their job: they resist glazing, stay cooler with modest water, and last longer than the bargain options I’ve used. The size spread handles a wide swath of common tasks, and the AutoStart pilot genuinely reduces the anxiety of starting on slick tile.

It’s not universal—there’s a hard cap on cutting depth, and you may need to supplement with a couple of sizes. But as a core kit for wet cutting in tile and similar materials, it’s reliable, efficient, and confidence-inspiring.

Recommendation: I recommend this kit for pros and committed DIYers who need clean, repeatable holes in porcelain and ceramic and value long-term durability. The AutoStart system, segmented rims, and overall cut quality justify the investment, and the included sizes cover most day-to-day plumbing and fixture penetrations. If you only need a one-off hole or you often work in thick slabs where deeper cores are required, consider buying individual sizes or a different system tailored to that use.