Choosing between garnet and steel abrasives is not about which is "better" – it is about which fits your site, your workpiece, and your production volume.

 

Garnet is a natural mineral abrasive. It fractures into sharp particles, generates low dust, transfers very low chloride, and is typically used once (or a few times) before disposal. Steel abrasives (steel shot and steel grit) are manufactured from hardened steel. They are highly recyclable – hundreds of cycles in a closed‑loop system – and are the economical choice for high‑volume production.

 

Here is how to decide by application.

 

Steel Structures (Bridges, Beams, Transmission Towers)

Open‑site blasting has no practical way to recover steel abrasives. Garnet is the standard choice. It achieves Sa 2.5–3.0 profiles, meets ISO 8501, and leaves no metallic residue. SEPPE recommends 30/60 mesh garnet for structural steel.

Shipbuilding & Marine Fabrication

For automated blast lines processing flat panels, steel grit in a wheel blast machine offers high throughput and low per‑part cost. For curved surfaces, weld seams, and touch‑up repairs, garnet is preferred – it reaches complex geometries and transfers very low chloride, critical for marine coating life. SEPPE supplies low‑chloride garnet for repair work and steel grit for high‑volume production.

Foundry & Casting Cleaning

Removing sand, scale, and flash from iron or steel castings is a high‑abrasion task. Steel shot and steel grit dominate here because they recycle hundreds of cycles in a closed‑loop wheel blast system. Garnet would fracture too quickly. SEPPE recommends steel shot or steel grit for foundry applications.

 

Internal Pipe Blasting (under ~600mm diameter)

Shot blasting equipment cannot enter small‑diameter pipes. Garnet pressure blasting is the only practical method. Low dust is also a safety advantage in confined spaces. SEPPE recommends 30/60 mesh garnet for pipe interiors.

Waterjet Cutting

This is a separate application where steel abrasives are not suitable. SEPPE supplies 80 mesh garnet specifically for waterjet cutting.

Contact SEPPE at info@seppe.cn. Tell us your substrate, coating specification, and site conditions – we will recommend the right abrasive grade for your project.