Diamond Grinding Consumables

Introduction

Diamond is the hardest known material and makes a great grinding abrasive for many hard materials. The advantages and disadvantages of grinding with diamond are as follows:

• Advantages:
  - Long lasting (most materials)
  - Hard and tough abrasive
  - Can be used for fixed, semi-fixed, and free abrasive application
• Disadvantages:
  - Rigid disks do not work well on ferrous metals (iron catalyzes diamond's conversion to graphite at grinding temperatures)
  - Needs to be conditioned or dressed for optimum operation
  - Expensive

Applications

Rigid diamond grinding disks are most useful for removing material from ceramics, cemented carbides, and ceramic matrix composites (CMCs), where SiC and alumina abrasives lack the hardness for efficient cutting. Diamond grinding disks also perform well on hard non-ferrous metals such as titanium and zirconium.

Note on steels: Rigid diamond grinding disks are generally not cost-effective for steels and other ferrous metals. The heat generated by fixed-abrasive disks catalyzes diamond's conversion to graphite in contact with iron, and SiC papers achieve the same result faster and at far lower cost. This limitation applies only to fixed-abrasive diamond grinding disks. Diamond polishing suspensions and sprays (typically 9 µm, 6 µm, 3 µm, and 1 µm) are the standard polishing abrasive for all steels, including hardened tool steels, and are used in nearly every steel preparation procedure (see our diamond polishing pages).

Metal vs. Resin Bond

There are two types of bonding for diamond grinding disks: metal and resin. Metal bonded diamond grinding disks are more aggressive and can produce more damage. Resin bonded disks will break down easier to produce a better surface finish, however, they typically have lower life.

PSA vs. Magnetic Backing

Diamond grinding disks are available with two backing options:

• PSA (Pressure-Sensitive Adhesive) Backing: Provides secure adhesion to grinding wheels. Ideal for standard grinding applications and when quick disk changes are needed.
• Magnetic Backing: Uses magnetic force to hold the disk in place. Best for magnetic grinding wheels and when you need easy removal and repositioning of the disk.

Products

Product Options

Choose from metal or resin bonded diamond disks, available in both PSA (pressure-sensitive adhesive) and magnetic backing options for different grinding applications.

Metal Bonded Diamond Disks

Resin Bonded Diamond Disks

Grit Selection Guide

Select the appropriate diamond grit size based on your material type, starting condition, and desired surface finish. Start with the coarsest grit needed to remove sectioning damage, then progress to finer grits.

Note: For materials requiring minimal damage, use resin-bonded disks with finer grits. For aggressive material removal, use metal-bonded disks with coarser grits.

Procedures & Parameters

Recommended Procedures

Follow these steps for optimal diamond grinding results:

Initial Setup

• Select the appropriate diamond disk based on material type and starting condition
• Ensure the grinding wheel surface is clean and flat
• For PSA-backed disks: Remove protective backing and firmly press disk onto wheel, working from center outward to avoid air bubbles
• For magnetic-backed disks: Place disk on magnetic wheel and verify secure attachment

Grinding Process

• Apply appropriate grinding fluid (water or oil-compatible) to the disk surface
• Start with light pressure and gradually increase as needed
• Use complementary (matched) head and base speeds, typically 200/200 rpm in the same direction, for uniform stock removal and minimal damage
• Maintain consistent fluid flow to prevent overheating and extend disk life
• Rotate specimen 90° between grits to ensure uniform material removal
• Thoroughly rinse specimen between grit changes to prevent cross-contamination

Disk Conditioning

Diamond disks require periodic conditioning to maintain optimal performance:

• When to condition: When cutting rates decrease or surface quality degrades
• Metal-bonded disks: Use a silicon carbide dressing stick or run on a sacrificial SiC paper to erode the metal bond and expose fresh diamond particles
• Resin-bonded disks: Use an aluminum oxide (Al₂O₃) dressing stick designed for resin-bonded wheels, or grind a sacrificial alumina specimen. The softer Al₂O₃ erodes the resin matrix without aggressively wearing the diamond. Avoid SiC dressing sticks on resin bonds; they can over-erode the resin.
• Frequency: Condition after every 10-20 specimens or when performance drops noticeably

Best Practices

• Use the finest grit possible for your starting condition to minimize damage
• Progress through grits systematically - don't skip intermediate sizes
• Monitor disk condition and replace when diamond particles are significantly worn
• Store disks in a clean, dry environment to prevent contamination
• For ceramics and hard materials, use lower pressure to reduce cracking risk

Process Parameters

Optimize your diamond grinding process by understanding key parameters:

Grinding Pressure

Force values below are per specimen. For central-load semi-automated heads, divide the indicated total head force by the number of specimens in the holder.

• Light pressure (2-4 lbs / 9-18 N per specimen): Recommended for ceramics, brittle materials, and fine grits to minimize damage
• Moderate pressure (4-8 lbs / 18-36 N per specimen): Standard for most hard materials and medium grits
• Heavy pressure (8-12 lbs / 36-54 N per specimen): Use only for very hard materials with coarse grits and metal-bonded disks
• Higher pressure increases material removal but also increases subsurface damage risk

Speed Settings

Lubrication

• Water: Most common choice, effective for most materials, prevents overheating
• Water-soluble oils: Recommended for water-sensitive specimens, provides better lubrication
• Oil-based fluids: Use for specific applications requiring enhanced lubrication
• Maintain consistent fluid flow throughout grinding cycle
• Ensure adequate fluid volume to prevent swarf buildup on disk surface

Troubleshooting