When abrasive discs stop being enough, the specialist accessories take over. Diamond blades cut the hard materials that ordinary wheels cannot: stone, tile, concrete and brick. Hole saws and core bits cut clean round holes through everything from a wooden door to a granite countertop. Pick the wrong one and you burn out an expensive accessory in minutes or crack the material; pick the right one and the job is quick and clean.

This buying guide explains diamond blades, hole saws and core bits in plain terms so you can match the accessory to the material every time. It pairs with our main guide on angle grinders in Panchkula and our hands-on guide to cutting marble and tile cleanly.

How a diamond blade actually cuts

A diamond blade has no teeth. Industrial diamonds are set into a metal bond around the rim of a steel core, and the blade cuts by grinding away the material with those diamonds. As the bond wears, fresh diamonds are exposed, so a good blade keeps cutting throughout its life. This is why diamond blades handle concrete, granite and porcelain where a toothed blade or abrasive wheel would fail or shatter.

The three diamond blade rim types

The rim design is the choice that matters most. Match it to the material and the finish you need.

Segmented rim

  • Visible gaps (gullets) between segments for cooling and dust clearance.
  • The fastest, most aggressive cut, and survives the heat of dry cutting.
  • Best for concrete, brick, block and rough masonry.
  • Will chip tile and polished stone, so keep it off finished surfaces.

Turbo rim

  • A continuous rim with a serrated, turbocharged edge.
  • Faster than a plain continuous rim while still leaving a reasonably clean edge.
  • Best for granite, hard stone and general masonry, and works wet or dry.
  • A strong all-rounder for site work.

Continuous rim

  • A smooth, unbroken diamond edge.
  • The cleanest, chip-free finish, though it cuts slower and is usually run wet.
  • Best for marble, polished granite, ceramic and porcelain tile where the edge shows.

A simple rule: segmented for speed and rough material, continuous rim for a clean visible edge, turbo when you want a bit of both.

Wet or dry, and getting the size right

  • Wet cutting cools the blade, extends its life, suppresses dust and gives the cleanest edge. Preferred for marble and polished stone.
  • Dry cutting is convenient but hotter and dustier. Use short passes to let the blade cool, and always wear a rated dust mask, since stone and concrete dust contains harmful silica.
  • Diameter must match the machine. Never fit a blade larger than your grinder and guard are rated for, and make sure the blade’s speed rating exceeds the machine’s speed.

KTC stocks diamond cutting blades and marble blades from Bosch (including zero-chipping types), Dongcheng, Cameron, Alex, Awant, Axtrim and Cumi, in the common 4-inch and 5-inch sizes and up.

Hole saws: clean round holes in sheet material

A hole saw is a cylindrical cutter with a pilot drill in the centre, used in a drill to cut round holes. The right type depends entirely on the material.

Bi-metal hole saws

  • Flexible bi-metal teeth for wood, plywood, plasterboard, plastic and thin metal.
  • The everyday choice for doors, panels and general fitting work.
  • KTC stocks Taparia bi-metal hole saws among others.

TCT (tungsten carbide tipped) hole saws

  • Carbide teeth for tougher material: hard board, fibre cement, brick and some metals.
  • Longer life on abrasive materials than bi-metal.
  • KTC stocks Bosch TCT, Taparia TCT, Shark and XPT hole saws.

Diamond hole saws

  • Diamond grit edge for tile, marble, granite and porcelain.
  • Run cool with water and start at an angle to avoid slipping.
  • KTC stocks diamond dry hole saw sets (for example MAF PRO) and marble core bits.

For larger or deeper holes, deep hole saws and adjustable hole saws are available too. Whatever the type, check the arbor (mandrel) and pilot drill suit the hole saw, and use a steady speed with light pressure.

Core bits: holes in stone, tile and masonry

Core bits are the specialists for round holes in hard materials.

Diamond core bits (marble core bits)

  • For clean holes in marble, granite, tile and porcelain, for taps, pipes and fittings.
  • Sold by diameter. KTC stocks marble core bits from 6 mm up to 67 mm and larger, from Sanwa, XPT, Xmarble and others.
  • Start at a slight angle, then bring upright, and keep the bit cool with water for a clean hole and long life.

Masonry core bits for rotary hammers

  • For larger holes in concrete, brick and block, for example running services, pipes and conduit.
  • Used in an SDS rotary hammer rather than a grinder or drill.

If your work involves both stone and masonry coring, it is worth keeping a small set of core bits in the sizes you use most, rather than buying one at a time on the job.

Quick match: accessory by material and job

  • Cut concrete, brick, block: segmented diamond blade
  • Cut granite, hard stone: turbo diamond blade
  • Cut marble, tile, porcelain (clean edge): continuous rim diamond blade
  • Round hole in wood, plastic, thin metal: bi-metal hole saw
  • Round hole in hard board, brick, some metal: TCT hole saw
  • Round hole in tile, marble, granite: diamond core bit
  • Large hole in concrete or block: masonry core bit in a rotary hammer

Get more life out of these accessories

  • Keep them cool: heat is the enemy of diamond tooling. Cut wet where you can, or use short passes when dry.
  • Do not force: let the blade or bit grind at its own pace. Forcing overheats and glazes the diamond.
  • Match speed to size: larger diameters run at lower speeds. Follow the rating on the accessory.
  • Check direction arrows: fit blades the right way round.
  • Store dry and flat: so nothing warps or corrodes.

And as always, run the machine safely: guard on, correct disc, full PPE. See our angle grinder safety guide.

What KTC stocks

Khandelwal Trading Co. carries a deep range of cutting and coring accessories for trade and retail customers across the Tricity:

  • Diamond cutting blades and marble blades in segmented, turbo and continuous rim styles (Bosch, Dongcheng, Cameron, Alex, Awant, Axtrim, Cumi)
  • Bi-metal, TCT and diamond hole saws, plus deep and adjustable types (Taparia, Bosch, Shark, XPT, Jon)
  • Marble and diamond core bits from 6 mm upward (Sanwa, XPT, Xmarble)
  • Masonry core bits for rotary hammers, arbors and pilot drills

Tell us the material and hole size and we will match the accessory. See more on our power tools page.

Frequently asked questions

Which diamond blade should I use for tile?

A continuous rim diamond blade for a clean, chip-free edge on tile, marble and porcelain. Keep segmented blades for concrete and rough masonry, as they chip finished surfaces.

Can a diamond blade cut metal?

Standard diamond blades are made for stone, tile, concrete and masonry, not metal. For steel, use a bonded abrasive cutting wheel instead. See our guide to angle grinder disc types.

What is the difference between a hole saw and a core bit?

A hole saw cuts round holes in softer sheet material like wood, plastic and thin metal. A core bit is built for hard materials like stone, tile and masonry, using diamond or carbide.

How do I drill a clean hole in granite or tile?

Use a diamond core bit of the right size, start at a slight angle to catch the ring, then bring it upright and keep it cool with water.

Why does my diamond blade stop cutting?

Usually overheating or glazing from forcing it or cutting too hot. Let it cool, cut wet if possible, and ease the feed. Dressing the blade on an abrasive block can re-expose the diamonds.

Blades, hole saws and core bits at KTC Tools, Panchkula

For the right diamond blade, hole saw or core bit, matched to your exact material and hole size, visit Khandelwal Trading Co. or reach us below.

  • Call: 94175 65977
  • WhatsApp: wa.me/919417565977
  • Visit: Shop No. 4, Street No. 2, Maheshpur, Sector 21, Budanpur, Panchkula, Haryana 134117
  • Trade enquiries: get a quote