Quick answer
Choose a grit blasting machine by workpiece size, required surface profile, production volume and site constraints: portable pots for field jobs, cabinets for small parts, and blast rooms for large fabrications.
Start with the workpiece
List the largest part you blast regularly — length, weight and whether it can be moved into a chamber. Parts that fit through cabinet doors belong in a cabinet. Oversized tanks, structures and frames need a blast room or portable open blasting.
Also note the substrate and coating goal (for example Sa 2½ before epoxy). That drives media choice and whether you need aggressive grit or a gentler bead finish.
Match the machine type
Portable pressure pots suit on-site rust and paint removal on steel structures, pipelines and tanks when you can manage dust and containment.
Cabinets keep abrasive and dust enclosed for small-to-medium parts with reclaim — better for workshops and repeatable finishing.
Blast rooms serve large fabrications and high throughput with recovery floors and dust collection. They cost more up front but protect operators and neighbouring processes.
Check utilities and duty
Confirm compressed-air capacity (CFM at working pressure), power availability and whether wet or vacuum blasting is required for dust-sensitive sites.
Share production volume (parts per shift) when you request a quote — under-sized pots and nozzles waste time; over-sized rooms waste capital.