Diamond Drill Bits for Sale: 6 Best Picks by Size & Price

Snap a bit halfway through a granite countertop and you lose the material, the time, and probably a customer. Picking the wrong diamond drill bits for sale online is an easy way to waste money on tools that glaze over, wobble, or crack tile instead of cutting clean holes through it. Size, bond hardness, and shank type all matter more than the price tag on the listing.

If you’re comparing options for drilling glass, porcelain, stone, or concrete, you need bits matched to the material and the hole diameter you’re actually working with, not a generic set that claims to do everything. This guide answers that directly: it lines up six proven picks by size range and price so you can match a bit to the job before you check out.

Below, we break down core bits, hole saws, and CNC-ready tooling from brands fabricators already trust, including Abaco and Weha, along with what each size handles best and where the price makes sense for shop volume versus occasional use. You’ll walk away knowing exactly which bit to add to your cart and why.

1. DeFusco diamond core drill bits for stone and tile pros

DeFusco’s diamond core drill bits are built for fabricators who drill granite, marble, and porcelain slabs every day, not once a month. These bits use a brazed or sintered diamond bond matched to the hardness of the stone, so they hold their edge through sink cutouts, faucet holes, and anchor points without glazing over. If you’ve burned through cheap import bits that dull after ten holes, this is the line that fixes that problem.

Sizes available

The lineup covers the diameters stone and tile shops actually use on a daily basis, from small anchor holes to full sink cutouts:

• 1/4" to 1/2" for anchor and hardware holes
• 3/4" to 1-1/4" for plumbing and electrical penetrations
• 1-3/8" to 2-1/2" for faucet and soap dispenser holes
• 3" and up for sink cutouts and drain openings

Each size ships with a standard arbor or threaded connection, so you’re not stuck buying a separate adapter kit just to mount the bit on your drill.

Best for

These bits are best for granite, marble, engineered stone, and porcelain tile, the exact materials countertop fabricators and tile installers cut through daily. Occasional DIYers drilling a single hole in a backsplash won’t see the value here. Shops running multiple slabs a week will, because the bond life translates directly into fewer bit changes and less downtime.

A bit that lasts through 200 holes instead of 20 pays for itself before lunch.

Price range

Expect to pay between $18 and $95 per bit, depending on diameter and bond type. Smaller anchor-hole bits sit at the low end, while large sintered bits for sink cutouts run closer to the top. Buying in multi-packs by size drops the per-unit cost noticeably if your shop burns through several sizes each week.

Where to buy

DeFusco Industrial Supply carries the full range directly, alongside compatible drills and wet-cutting accessories, so you can order the bit and the hardware that runs it in one checkout. Shops that fabricate stone or tile regularly should look here first before shopping around for one-off bits from general hardware retailers.

2. Small diamond drill bits for glass and jewelry

Glass, gemstones, and beads crack under the wrong pressure, so these jobs call for fine diamond-coated tips rather than the core bits used on stone. The coating is thin and electroplated, built for precision on brittle, thin materials rather than brute cutting through slabs. Jewelry makers and hobbyists drilling beads, pendants, or glass ornaments need control more than speed here.

Sizes available

These bits run much smaller than stone tooling, matched to delicate work rather than structural holes:

• 0.8mm to 1.5mm for beads and small gemstones
• 2mm to 3mm for pendant drilling and glass etching
• 4mm to 6mm for larger glass panels and ceramic beads

Most come with a straight shank sized for rotary tools and mini drill presses, not standard drills.

Best for

Small diamond bits suit glass artists, jewelry makers, and hobbyists working on thin, brittle material where a standard masonry bit would shatter the piece instantly. They’re not built for load-bearing holes or repeated daily production runs.

Precision beats power when the material is thin enough to crack under a heavy hand.

Price range

Because of the small diameters and light-duty coating, these bits are cheap, typically $3 to $15 per bit or $10 to $25 for a multi-size set. That low cost also means shorter lifespan, so expect to replace them more often than stone-grade tooling.

Where to buy

DeFusco stocks small-diameter diamond bits alongside its core drill lineup, giving hobbyists and pros a single supplier for both delicate and heavy-duty diamond tooling.

3. Diamond hole saws for tile and ceramic

Hole saws differ from core bits in one key way: they cut a ring around the waste material instead of grinding through the full diameter, which means faster cuts and less strain on your drill. For porcelain, ceramic, and glazed tile, that speed advantage matters, especially when you’re cutting dozens of holes for plumbing fixtures or light fixtures on a single job. Diamond hole saws also run cooler than solid core bits at comparable sizes, which cuts down on tile cracking near the edge of the hole.

Sizes available

Most hole saws in this category cover the diameters tile installers need for fixtures and fittings:

• 1/4" to 1" for small fixture and anchor holes
• 1-1/4" to 2" for standard plumbing penetrations
• 2-1/2" to 4" for larger drain and vent openings

Best for

These saws are built for ceramic and porcelain tile installers cutting fixture holes in walls and floors, not for stone slab fabrication. Bathroom remodelers and tile setters doing repeat plumbing cutouts get the most value here, since the faster cut time adds up across multiple jobs per week.

Faster cutting means less heat, and less heat means fewer cracked tiles at the edge of the hole.

Price range

Expect $12 to $60 per saw, with larger diameters and premium diamond coatings landing at the top of that range.

Where to buy

DeFusco carries diamond hole saws sized for standard plumbing and fixture work, stocked right alongside the core bits tile pros already order.

4. Sintered diamond core drills for concrete and brick

Concrete and brick chew through electroplated coatings fast, so these jobs need bits with diamond bonded all the way through the segment, not just plated on the surface. Sintered diamond core drills press diamond grit into a metal matrix under heat and pressure, so as the outer layer wears down, fresh diamond keeps getting exposed underneath. That’s the difference between a bit that lasts one job and one that lasts a season of foundation work.

Sizes available

These drills scale up fast compared to tile or stone tooling, since concrete and brick jobs usually call for wider penetrations:

• 1/2" to 1" for anchor bolts and rebar clearance holes
• 1-1/4" to 2" for conduit and plumbing runs through block walls
• 2-1/2" to 4" for HVAC and larger utility penetrations
• 5" and up for core sampling and structural openings

Best for

Contractors drilling reinforced concrete, cinder block, and brick for utility runs or anchor installations get the most out of this category. Sintered bonds resist the abrasive aggregate in concrete far better than plated coatings do, which matters most on jobsites where crews drill dozens of holes a week.

A sintered bond wears down instead of wearing out, and that’s what keeps concrete crews on schedule.

Price range

Expect $25 to $150 per bit, with price climbing alongside diameter and segment length. Larger core-sampling sizes sit at the top of that range.

Where to buy

DeFusco stocks sintered core drills sized for contractor-grade concrete and masonry work, matched to the wet-cutting equipment already in the catalog.

5. Diamond drill bit sets for rotary tools

Rotary tool sets bundle multiple bit sizes into one kit, built for the guy who drills a handful of holes a week instead of hundreds a day. These sets pair a Dremel-style shank with electroplated diamond tips, so they fit the rotary tools already sitting in most home shops and side-hustle setups. If you’re not ready to invest in dedicated drills and arbors for every job, a set covers glass, tile, and light stone work without buying six separate bits.

Sizes available

Most kits stack sizes into one case so you’re covered across small projects without ordering piece by piece:

• 1mm to 3mm for fine detail and jewelry work
• 4mm to 6mm for tile trim and small fixture holes
• 8mm to 10mm for larger decorative cuts

Sets typically include 5 to 20 bits, with the larger kits also throwing in a dressing stone to clean glazed tips.

Best for

These sets suit hobbyists, side-job contractors, and maintenance techs who need occasional holes in tile, glass, or soft stone rather than daily production drilling. Full-time fabricators will wear through a set fast and should look at dedicated core bits instead.

A bit set earns its keep on variety, not volume.

Price range

Expect $15 to $45 per set, depending on bit count and coating quality. That’s cheaper per bit than buying individually, but the tradeoff is shorter life on each tip.

Where to buy

DeFusco offers rotary-compatible diamond sets alongside its full-size drills, so occasional users and pros can shop the same catalog.

6. Extra-long diamond drill bits for deep holes

Some jobs need a bit that reaches further than a standard core drill ever will, think thick slabs, deep wall penetrations, or drilling clean through a countertop and the cabinet below it in one pass. Extra-long diamond drill bits extend the shaft length well past standard bits while keeping the same diamond segment at the tip, so you get depth without switching to a completely different tool setup. Plumbers and stone fabricators working on thick installations reach for these when a regular bit simply won’t clear the material.

Sizes available

Length is the defining spec here, not just diameter, since these bits are built to punch through thicker material than standard tooling handles:

• 1/4" to 1" diameter with 12" to 18" shaft lengths
• 1-1/4" to 2" diameter with 18" to 24" shaft lengths
• Extension adapters available for select sizes to add another 6" to 12" of reach

Best for

These bits suit thick stone slabs, double-layer walls, and deep utility penetrations where a standard-length bit would bottom out before finishing the hole. Anyone drilling through a single tile or thin panel doesn’t need the extra length and should stick with standard core bits instead.

Depth solves a problem length alone can’t fix, and that’s exactly what these bits are built for.

Price range

Expect $30 to $120 per bit, with cost climbing alongside both diameter and shaft length.

Where to buy

DeFusco stocks extra-long core drills for shops that regularly hit thicker material, keeping them shelved next to standard-length bits for easy comparison.

Picking the right diamond bit for your next job

Matching the bit to the material still beats chasing the lowest price per unit. A sintered core drill built for concrete will outlast three cheap electroplated bits on the same job, and a fine glass tip will crack the second you push it through porcelain. Diameter and shaft length matter just as much as bond type, so check both against the hole you’re actually drilling before you check out.

Run through the six categories above, match your material and hole size, and you’ve already narrowed the field to one or two bits worth ordering. That’s the whole point of comparing diamond drill bits for sale by size and price instead of grabbing whatever shows up first in search results.

When you’re ready to order, shop DeFusco’s full diamond drill bit lineup and get bits built for the job, not just the listing photo.