Cast Steel Shot
Cast steel shot is a spherical metal abrasive widely used for metal surface treatment. It is produced by melting scrap steel, atomizing the molten steel into spheres, followed by quenching and tempering. It is primarily applied for derusting, sand removal, descaling and shot peening, featuring high cost performance and reusability.
Basic Properties
Composition: Mainly high carbon (0.85%–1.2% carbon), containing manganese, silicon and other elements with low impurities.
Appearance: Spherical or nearly spherical shape with smooth surface and high sphericity.
Hardness: Regular grade: HRC 40–50; high-carbon grade: HRC 57–62.
Particle Size: Complying with SAE standards, ranging from S230 (0.2 mm) to S780 (2.5 mm). Larger specifications of 3–10 mm are also available.
Service Life: Recyclable for 2000 to 3000 cycles, with minimal dust and low consumption.
Production Process
Melting: Melt qualified scrap steel and alloys in an electric arc furnace or medium frequency furnace at a temperature above 1500°C.
Atomization: Molten steel is impacted by high-pressure water or centrifugally atomized to form spherical droplets which solidify into shots.
Heat Treatment: Quenching for hardness improvement and tempering for toughness enhancement to stabilize internal structure and hardness.
Screening and Grading: Classify products by particle size and sphericity, and remove hollow or deformed particles.
Main Applications
Surface Cleaning: Sand removal for castings, rust elimination and descaling of forgings, steel plates and steel structures.
Coating Pretreatment: Increase surface roughness and coating adhesion for ships, bridges and containers.
Shot Peening: Treat gears, springs, crankshafts, bearings and other components to extend fatigue life and improve stress corrosion resistance.
Other Uses: Pipeline descaling, stone cutting and mould cleaning.
Comparison with Steel Cut Wire Shot
Cast Steel Shot: Spherical shape, good fluidity and uniform coverage with moderate hardness. Ideal for general cleaning and shot peening.
Steel Cut Wire Shot: Cylindrical shape with slight edges, strong cutting power and 30%–50% longer service life. Suitable for removing heavy rust and harsh working conditions.
Selection Guidelines
Particle Size: Coarse shots (1.0–2.5 mm) for rapid removal of heavy contaminants; fine shots (0.2–0.6 mm) for fine surface treatment.
Hardness: HRC 40–50 for ordinary steel workpieces; HRC 57–62 for high-hardness parts such as gears and bearings.
Working Conditions: Cast steel shot is the preferred choice for shot blasting machines. A small amount of steel cut wire shot can be mixed for heavy rust removal.
Standards & Production Areas
National Standard: GB/T 18838.3–2008
International Standards: SAE, ISO
