A 9-inch angle grinder, while powerful, is generally not recommended for amateur use due to its size, weight, and extreme power. It's a heavy-duty tool primarily for professional metalworking, concrete cutting, and demolition tasks where large material removal is needed. For amateurs, a 4.5 or 5-inch grinder is far safer and more manageable for common DIY tasks like sharpening, light grinding, or cutting smaller materials. The 9-inch model poses significant kickback risks and demands experienced handling.