The third consideration when choosing a nozzle is the composition of the lining inside the bore. Harder materials will be more resistant to wear, but are more expensive to replace and are prone to cracking under rough handling. There are four basic types of carbide nozzles.
Tungsten Carbide: This is the least durable of the carbide nozzles, but relatively cheap and resistant to impact. Suitable for blasting slag, glass and mineral abrasives.
Silicon carbide: Impact resistant and durable like tungsten carbide, but lighter. Causes less operator strain.
Boron Carbide: Extremely hard and durable, but brittle. Up to ten times the longevity of tungsten carbide.
Composite Carbide: Some manufacturers produce their own composite carbide nozzles, which are even harder than boron carbide.