Know Your Nozzles:
Blast Nozzle Materials
Understand the Advantages and Disadvantages of the
Used to Make Blast Nozzles
Cast Iron Nozzles
Rarely used today. They wear out after 6 to 8 hours of blasting.
Used with non-aggressive abrasive in light-duty equipment and in blast cabinets.
Aluminum Oxide Nozzles
Cost less than carbide-lined nozzles (discussed below). A good fit for low-use applications or when price is more important than service life.
Carbide Lined Nozzles: Tungsten, Silicon, and Boron
The most popular choice for the majority of blasting applications due to their long life, even though carbide nozzle liners tend to be brittle. To protect against this brittleness, Clemco nozzle liners are encased in a jacket, usually made from metal, urethane, or rubber.
Tungsten-Carbide Lined Nozzles
Hard and heavy, provide excellent wear resistance.
Tungsten carbide is sintered, a process that uses
extreme heat and pressure to produce one-piece
liners in a mold. While sintering strengthens tungsten
carbide, it also contributes to brittleness. Still,
tungsten-carbide lined nozzles are an excellent choice
to use with steel grit, steel shot, or any iron abrasive
because the high density of steel abrasive causes c
hipping in other carbide liner materials. Tungsten-carbide
lined nozzles also are an excellent choice when mineral or
coal slag abrasive is used in applications with rough handling.
Tungsten-carbide lined nozzles last from 300 to 400hours
when used with expendable abrasive and are less likely to
chip than longer-lasting silicon-carbide lined nozzles.
Silicon-Carbide Lined Nozzles
Developed from research on lightweight and
durable materials for the aircraft and aerospace
industries. Silicon-carbide lined nozzles
weighs 42% less than comparable tungsten-
carbide lined nozzles, making them easier
to hold for long durations. With expendable
abrasive, silicon carbide lasts between
400 to 600 hours, but it chips more easily than tungsten carbide
The longest-wearing carbide lined nozzles. Boron-
carbide lined nozzles are extremely tolerant of
sharp abrasives, such as aluminum oxide and
silicon carbide, and are best suited for applications
that do not require rough handling. With expendable
abrasive, boron-carbide lined nozzles last between
750 and 1500 hours. The price of a boron-carbide
lined nozzle is two to three times more than for
a comparable silicon-carbide lined nozzle or tungsten-
carbide lined nozzle; however, the cost per operating
hour for boron carbide as compared to tungsten and
silicon carbide decreases as more aggressive abrasive is used.