Steel shot Vs steel grit differences hardness application-Honest Horse china garnet sand

Steel shot Vs steel grit differences hardness application

Appearance and working principle

Steel shot is spherical. It cleans by hammering and compression, leaving smooth, rounded pits on the metal surface — ideal for cleaning and shot peening.

Steel grit is sharp and angular. Its edges cut and scrape away rust, mill scale, and old coatings, leaving a sharp anchor profile for coating adhesion.

Hardness (40–68 HRC)

Steel shot: 40–51 HRC is the most common range — good toughness, low breakage, long cycle life. Harder shot is used for shot peening.

Steel grit comes in three hardness grades:

GP — tough type, for general rust removal
GL — medium hardness, for removing oxide scale
GH — high hardness, for hard, stubborn deposits

How to choose

Choose steel shot when you need a smooth, clean surface with light rust, or when shot peening for fatigue strength (use harder grades in this case).

Choose steel grit when you face heavy rust, thick mill scale, or old paint layers, and when a sharp anchor profile is required for heavy coating adhesion. Use GP or GL for heavy rust and mill scale, and GH for hard, stubborn deposits.

In practice, many blast rooms use a shot/grit blend — grit cuts the heavy contamination first, then shot smooths the profile. The right mix depends on your surface condition, target profile (e.g., 40–75 μm), and blasting equipment.

Summary

Shot hammers and smooths; grit cuts and anchors. Choose based on the contamination to remove and the profile your coating requires. Unsure which grade fits your process? Suppliers can provide hardness data, size distribution, and test samples to verify performance before you order.