When evaluating a rock splitter, the most critical factor is the splitting force, which typically ranges from 200 to 600 tons for handheld units and up to 5,000 tons for large machine-mounted splitters. You must also verify the wedge length and diameter to ensure they match your pre-drilling capabilities. High-quality splitters should use specially heat-treated alloy steel for the wedges to prevent deformation under extreme pressure. Additionally, check the hydraulic pump pressure rating, which usually operates between 50-60 MPa for optimal performance.