Using 3M Radial Discs for Jewellery Polishing

If you work with silver, gold, or mixed metals, you’ll know how important it is to have the right polishing tools. One of the most popular choices among jewellers and silversmiths are 3M Radial Discs – versatile, colour-coded polishing wheels that make finishing and repair work faster, cleaner, and more precise.

Whether you’re a professional jeweller or a hobbyist, this guide explains what 3M Radial Discs are, how to use them, and which sizes and grades are best for your workbench.

3M Radial Discs are flexible abrasive wheels designed specifically for fine metal finishing and jewellery polishing. They have thin radial “bristles” that reach into textures, crevices, and detailed areas that traditional polishing mops can’t access.

Why jewellers love them:

• No need for messy polishing compounds – they’re ready to use.

• Colour-coded grades make selecting the right grit simple.

• Perfect for polishing delicate details such as filigree and engraving.

• Reach into solder joins, etchings, and textured surfaces.

• Very fine grades (like the 1 micron light green) can be used safely next to hard stones.

• Ideal for jewellery repairs, touch-ups, and polishing small areas.

Tip: You’ll usually use them in sets of three, mounted on a reusable screw-top mandrel, with a Pendant Motor or Micromotor.

3M Radial Discs come in different diameters, but the most popular for jewellers are 19mm and 25mm.

• 19mm discs – Best for fine jewellery work. They’re thinner, more flexible, and available in finer grades.

• 25mm discs – Slightly larger and stiffer, useful for broader surfaces and heavier polishing.

You don’t need every grade – just the right progression. A common set-up for jewellery work is:

• 80 grit (yellow) – for cleaning and shaping.

• 400 grit (blue) – for smoothing.

• 6 micron (peach) – for fine pre-polish.

• 1 micron (light green) – for the final high polish.

This 4-step system works beautifully for most jewellery, silver, and gold polishing projects.

Tip: Remember: you’ll need at least three discs per grade for the best results.

To use your discs, you’ll need a screw-top mandrel. These are reusable and available in two spindle sizes:

• 2.35mm – the standard size for jewellers using pendant motors.

• 3mm – often used in engineering or larger micromotors.

Tip: Keep one mandrel per grade to save time switching discs.

1. Unscrew the mandrel (by hand or with a small screwdriver).

2. Thread three discs of the same grade onto the mandrel – all legs must face the same direction.

   • Don’t mix new and used discs.

   • If mounted backwards, the legs will fly off when polishing!

3. Tighten the mandrel securely – firm enough to hold, but not so tight you can’t change them later.

Tip: When looking down at the discs on the mandrel, the legs should face anticlockwise.

If you prefer using a bench polisher (like the Foredom bench lathe), larger radial wheels are available:

• 50mm & 75mm wheels – Perfect for small bench polishers, with reusable plastic taper centres.

• 150mm (6”) wheels – Great for full-size bench polishers. Adjustable centres fit common arbors.

Tip: 150mm 3M wheels can be costly, so we also stock excellent non-3M alternatives in the same size.

• Use 4+ discs of the same grade for best results.

• Mount them with a plastic or screw centre, ensuring all legs face the same direction.

• Tighten securely, then wind onto the taper pigtail of your bench polisher.

For jewellers, silversmiths, and hobbyists, 3M Radial Discs are one of the most reliable and versatile polishing tools available. They:

• Reduce polishing time.

• Eliminate the need for messy compounds.

• Preserve detail in delicate jewellery pieces.

• Deliver a professional finish every time.

Whether you’re repairing antique jewellery, polishing your latest silversmithing project, or refining hobbyist creations, 3M Radial Discs give you precision and control.

Tip: Explore our full range of 3M Radial Discs, mandrels, and accessories to set up your polishing kit today.