Diamond tip drill bit are specialized tools commonly used for working with hard, brittle materials, stone, and for precision machining. Unlike regular drill bits, their diamond-coated tips allow them to cut through the hardest materials—since diamond is the hardest substance in nature, with a Mohs hardness of 10.

I’ve compiled some information on diamond tipped drill bits, including their characteristics, classifications, uses, sizes, and factors that influence their price.

what is a diamond tip drill bit

diamond tip drill bit are tools for working with hard and brittle materials. Unlike conventional drill bits designed to cut softer materials, these drill bits utilize an industrial diamond coating to abrade the surfaces of extremely tough materials like porcelain, stone, and concrete. Diamond’s unparalleled hardness is key to the drill’s breaking power, enabling it to easily penetrate materials that would dull and wear out traditional drill bits. It also ensures high precision, preventing the target surface from being irregularly broken.

A typical diamond drill bit consists of two main parts: the body and the diamond tip.

1: The Body

Usually made of high-strength steel, it provides the stability and strength needed for drilling. Its shape and length determine how deep you can drill. The bottom of the body, called the shank, houses the drill tip.

2: The Diamond Tip

This is the core of the bit. It’s covered in tiny industrial diamond particles. Instead of cutting, these diamonds grind away the material, turning it into a fine powder. The way these diamonds are attached to the tip determines the bit’s quality and lifespan. there are two types of attachment: electroplated and sintered.

The tip shape also varies. There are solid tips diamond tip drill bit for small, precise holes and hollow tips diamond core drill bits for large holes.

You’ve undoubtedly seen or used it in the following industries:

• Construction and renovation;

• Stone and glass processing (yes, glass is also possible);

• Precision machining (such as ceramics and jewelry).

Types of diamond tip drill bit

Diamond Core Drill Bits

Diamond core drill bits are distinguished by their hollow, cylindrical shape. They’re engineered to drill large-diameter holes by grinding only the outer edge, leaving a solid core of material in the center. This design makes them incredibly fast and efficient since they remove less material and generate less heat. They’re commonly used for jobs like installing plumbing and electrical conduits or cutting holes for sink faucets.

Diamond Core Drill Bits

Diamond Solid Drill Bits

Diamond solid bits are different. They have a solid, pointed tip and are designed for drilling smaller, more precise holes. Instead of cutting just the edge, they grind away all the material within the hole’s diameter. This makes them the perfect tool for intricate work, such as drilling holes in glass bottles for art projects or for jewelry making.

Diamond Solid Drill Bits

Diamond Solid bits and Diamond core drill bits: What is the difference?

Both are diamond-tipped bits, but their functions and shapes are different.

Diamond Core Drill Bits: These are hollow and cylindrical. They’re designed for drilling large, clean holes by grinding only the outer edge of the cutting area. They’re best for jobs like installing plumbing or drilling into concrete.

Diamond Solid Bits: These have a solid tip. They grind away all the material to create a small, precise hole. They’re the right tool for intricate work on glass or for jewelry making.

Which diamond tip drill bit should I use?

Need to drill large holes in hard rock, concrete, or brick walls

Recommended drill bit: Diamond Core Drill Bits.

These drill bits are hollow and grind only the edges of the hole, making them extremely efficient, removing the least amount of material in the shortest possible time. They are particularly suitable for preparing holes for pipes, wires, or large fixtures in construction and renovation projects.

Need to drill small holes in glass, gemstones, or ceramics

Recommended drill bit: Diamond Solid Drill Bits.

These drill bits have a solid tip, allowing for a finer grind. They provide greater precision and are ideal for crafts, jewelry, or drilling holes in delicate ceramics.

Need to perform fine engraving or grinding

Recommended drill bit: Diamond Spherical Burrs or other shaped engraving burrs.

These tools have spherical or other specialized tips designed for precise grinding, carving, and shaping, rather than simple drilling. They are ideal for crafts, gemstone carving, and other tasks.

Need to drill holes in tile or marble for bathroom fixtures or kitchenware installations

Recommended drill bit: Diamond core drill bits, sized to match the installation hardware.

Drilling large holes in these materials requires smooth, clean cuts to prevent tile cracking or marble chipping. Core drill bits cut with an abrasive motion, producing cleaner holes than other drill bits.

Need to drill holes in very hard materials (such as quartz and agate)

Recommended drill bit: Sintered diamond drill bits.

The diamond grains in sintered drill bits are multi-layered, making them more durable than electroplated drill bits. As the outer layer wears away, a new layer of diamond is exposed, ensuring a longer lifespan and more consistent cutting performance.

In general, Diamond bits are designed for hard, brittle materials. They are not for use on soft materials like wood, plastic, or metal(Yes, diamond drill bits cannot drill metals such as hardened steel.), which would clog the bit. If you have these needs, I suggest you choose a traditional drill bit.

Sintered diamond drill bits and electroplated diamond drill bits

These are the two main ways of setting diamond-tipped drill bits, which determine the performance and life of the drill bits.

Sintered diamond drill bits

Features: This is a more advanced process. Multiple layers of diamond particles are mixed with metal powder and then sintered together under high temperature and pressure to form a hard composite tip.

Advantages: Extremely durable and very long-lasting. Even if the outermost diamond layer wears away, a new layer of diamond particles remains exposed to continue working. This makes it an excellent choice for high-intensity, frequent use.

Electroplated diamond drill bits

Features: This is the most common setting method. It uses an electroplating process to attach a layer of diamond particles to the metal tip of the drill bit.

Advantages: Low cost and affordable. Ideal for DIY projects with infrequent use.

Disadvantages: Limited lifespan. Once the surface layer of diamond particles wears away, the drill bit loses its cutting ability and needs to be replaced.

Disadvantages: High cost and more expensive.

If you are an occasional user, a plated drill bit will suffice. But if you are a professional who needs to frequently handle hard materials, then investing in a durable sintered drill bit will be more cost-effective in the long run.

Sizes of diamond drill bits

Diamond drill bits are typically sized in millimeters (mm) or inches (inches). They can be roughly divided into three categories based on their diameter, allowing you to choose the right size.

Small-Sized Drill Bits (< 5mm)

These drill bits have a very small diameter (even 1mm diamond bits) and are suitable for delicate work requiring extreme precision.

Applications:

Jewelry making and gemstone drilling.

Drilling small holes in glass or ceramic artwork.

Precision model making and electronic equipment repair.

Medium-Sized Drill Bits (6mm – 25mm)
Common examples include 6mm diamond drill bits, 8mm diamond drill bits, 10mm diamond drill bits, 1/8 diamond bits, 1/4 diamond bits, 3/4 diamond bits, 3/8 diamond bits, and 3/16 diamond bits.

This is the most common size range and has a wide range of uses, covering nearly all home renovation and DIY projects.

Applications:

Drilling holes in tiles for installing bathroom fixtures (such as towel racks and shower heads).

Drill holes in countertops for faucets or soap dispensers.

Drill holes in walls for outlets or switch boxes.

Large-size drill bits (> 25mm)
Common drill bits include: 32mm diamond core drill bits, 100mm diamond bits, 1″ diamond bits, 1 1/8 diamond drill bits, 1 1/4 diamond bits, 1 1/2 diamond drill bits, and even the largest 8 inches.
These large-diameter drill bits are primarily used for heavy-duty and specialized construction projects and are typically diamond hollow drill bits.

Uses:

Installing pipes, vents, or air conditioning lines.

Opening large holes in concrete or brick walls for large pipes or wires.

Used for machining tasks requiring large apertures in industrial manufacturing.

Factors Affecting Diamond Drill Bit Cost

You might be concerned about the cost of diamond drill bits, as I am. So I’ve compiled some factors that influence cost.

1. Diamond Setting Method
   As we mentioned earlier, this is the most significant factor affecting price.

Electroplated: This process is the least expensive, as it uses only one layer of diamond particles, making it the cheapest. (However, it can be very cost-effective for less intensive use.)

Sintered: This process is more complex, requiring multiple layers of diamond particles. It is extremely durable, so the price is usually several times higher than electroplated drill bits.

2. Diamond Quality
   The purity and size of industrial-grade diamonds also affect cost. Higher-quality, more uniform diamond particles provide better cutting performance and longer life, but also come at a higher price.
3. Drill Body Material
   The drill body is typically made of high-strength steel. The higher the grade of steel used, the more durable the drill bit, but the higher the cost.
4. Size and Shape
   Size: Generally speaking, larger drill bits require more material and are more expensive to manufacture.

Shape: Special shapes, such as those used for engraving or chamfering (e.g., diamond-shaped drill bits), are more complex to manufacture and therefore more expensive.

diamond tip drill bit Maintenance Tips

Proper maintenance can significantly extend the life of diamond drill bits and ensure efficient drilling every time. Here are a few key you should know:

1. Always use water for cooling
   This is the most important maintenance rule. Diamond drill bits grind materials through friction, generating a significant amount of heat. Without water, heat builds up quickly, leading to the following problems:

Always ensure a steady stream of water while drilling, either dripping from a water bottle or using a sponge.

2. Keep it clean
   After each use, clean the drill bit tip and shank of any debris and dust. This residue can affect the drill’s efficiency the next time it is used and may cause the drill bit to clog or overheat. Wipe with a brush or clean cloth.
3. Proper Storage
   Store drill bits in a dry, dust-free place. If possible, use a dedicated tool box to prevent drill bits from banging against each other, as even a hard diamond tip can be damaged by impact. This also prevents rust on the metal shank.