Abrasives in cutlery: role and use

In the manufacture of a knife, abrasives are used at every stage: shaping of blades and handles, grinding after machining, roughening of hard materials such as metal or exotic woods, and surface finishing. The abrasive is not a secondary accessory - it determines the visual and functional quality of the final result. Too coarse a grit leaves marks, too fine a grit rubs without removing material. A regular progression of grits is the key to clean work.

Cutlers mainly use abrasive belts mounted on belt sanders, but also sheet abrasives for hand work, particularly on curved parts of handles or hard-to-reach areas. The diversity of abrasive media and materials means that the tool can be adapted to every situation.

Different types of abrasive grain

The choice of abrasive grain depends on both the material being worked and the desired result. The main minerals used in cutlery are :

• Corundum (aluminum oxide) - versatile grit, suitable for wood, bone and composite materials. Good durability/price ratio for regular use.
• Zirconium - self-sharpening, highly resistant grit, recommended for stainless steels and hard metals. Extended service life under high pressure.
• Cubitron (3M ceramic) - high-performance grit for steels and stainless steels. Fast stock removal, reduced heat, excellent durability. Recommended for intensive work.

Which grit size to choose?

Grain size is expressed in "grit": the lower the number, the coarser and more aggressive the grain. A typical progression in cutlery:

• 40-80 grit: roughing, shaping, rapid material removal
• Grains 120-240: grinding, removal of welding or machining marks
• Grains 320-400: satin finishing, surface preparation before finishing
• 600 grit and over: fine finishing, satin to gloss finish

How to choose abrasives for cutlery?

Several criteria guide your choice:

• The material being worked: wood accepts standard corundum, while stainless steels require zirconium or cubitron to avoid loading the abrasive.
• The machine used: check that the belt dimensions (length × width in mm) are compatible with your belt sander.
• Desired level of finish: for a fine satin finish, allow for a minimum grit size of 400.
• Frequency of use: for intensive or professional use, cubitron justifies its extra cost by its durability.

For craftsmen just starting out, 120 and 240-grit corundum is a good starting point: versatile, affordable and available in standard sizes. For steels and finishing work, the switch to zirconium or cubitron is a quick and easy one.

Mercorne and abrasives: a selection designed for the workshop

Mercorne has been offering selected materials and consumables for cutlers for 34 years. Our range of abrasives follows this logic: workshop-tested references, in the most commonly used formats, at grain sizes covering the entire manufacturing process. Products are dispatched the same day they are ordered (Monday to Friday), with free delivery for orders over €90, and returns accepted within 15 days.

Frequently asked questions about cutlery abrasives

What's the difference between corundum and cubitron?

Corundum (classic aluminum oxide) is a versatile, economical grit suitable for wood and soft materials. Cubitron is a ceramic grit developed by 3M, far more resistant and self-sharpening, designed for hard steels and intensive use. Cubitron removes more material, heats up less and lasts longer - its higher price is generally offset by its longer life.

Can the same abrasives be used for wood and metal?

Technically yes, but it's not optimal. Standard corundum is suitable for both materials for small jobs. For metal - especially stainless steel - zirconium or cubitron are preferable: they don't load as quickly and maintain their effectiveness. Using a loaded wood abrasive on stainless steel means working with a dull grain.

How can I tell if a sanding belt is worn?

A worn belt removes less material at equal pressure, tends to slide over the surface instead of cutting, and may leave irregular marks. On fine-grained belts, the surface loses its abrasive appearance and becomes smooth to the touch. It's better to change the belt too early than too late: a worn belt heats up more and can mark parts.

What belt sizes do you most often order?

The most common sizes for craft cutlery are 50 × 1220 mm and 75 × 2000 mm, depending on the model of belt sander used. Always check the dimensions compatible with your machine before ordering - each sander has its own tolerances.