Stainless Steel Blasting

Overview

Using carbon-steel-based abrasives such as standard steel shot/grit on stainless steel surfaces causes iron contamination on the surface and, as a result, a reduction in corrosion resistance; for this reason, consumables that carry no contamination risk — such as stainless steel shot or glass beads — should be preferred. Hard, angular abrasives like aluminum oxide increase surface roughness and reduce durability, while round, smooth-surfaced abrasives (glass beads, stainless steel shot) produce a non-sharp, satin-finish, low-glare texture on the surface; this texture increases resistance to scratching, corrosion and cracking.

Blasting thin stainless steel sheets (below 0.4 mm) is not recommended, as it can create internal stress in the material leading to warping and buckling; where unavoidable, both surfaces must be blasted simultaneously. Blasting pressure and abrasive flow rate must be carefully controlled to achieve the desired surface texture. Observations show that as surface roughness (Ra) decreases, corrosion resistance increases: surfaces left with high roughness (Ra > 1.0 micron) have lower corrosion resistance than smoothly blasted surfaces (Ra < 0.5 micron).

Recommended Abrasives for Stainless Steel

• Glass Beads — light-toned, smooth and bright surface
• Stainless Steel Shot — lightly dimpled, hardened satin surface
• Ceramic Beads — balanced abrasion, controlled roughness
• Silicon Carbide — darker and rougher texture, aggressive cleaning

As approximate values, when abrasive size is selected in the 80–600 mesh range, the resulting surface roughness varies between Ra 1.80–0.13 microns (for example, a 600 mesh abrasive yields Ra ≈ 0.13 microns) — the abrasive size should be selected accordingly based on the desired texture fineness.

The consumable used in blasting must not contain any ferritic/carbon-steel-based particles or sand — these can cause iron contamination when they come into contact with the stainless steel surface. Contact Saykar to select the abrasive, machine and equipment best suited to your application.