Sanding is one of those processes where the tool often gets blamed before the technique does. When results aren’t clean or consistent, people usually assume the disc is the problem. Sometimes that’s true. Other times, it’s about how the disc is being used.
This comes up often with 150mm sanding discs, which sit in the middle ground. They’re not small detail discs, and they’re not large industrial pads either. They’re chosen because they offer balance.
Why 150mm Discs Are So Common
A 150mm disc covers enough surface area to work efficiently without feeling hard to control. That size allows for steady movement across panels, timber, metal, or composites without creating uneven pressure points.
Smaller discs can feel jumpy. Larger ones can feel heavy or harder to manage. The 150mm size tends to sit right in between, which is why it’s used so widely in workshops. Sanding isn’t about removing as much material as possible in the shortest time. It’s about removing just enough, evenly. With 150mm sanding discs, the focus is usually on control.
Where Diamond Sanding Discs Fit In
Diamond sanding disc are used when surfaces are especially hard or abrasive themselves. Stone, concrete, ceramics, and some composite materials quickly wear out standard abrasives.
Diamond discs don’t behave the same way as traditional sanding discs. They don’t rely on grit breaking down. Instead, they maintain their cutting edge for longer periods. This makes them useful when consistency and durability matter more than speed.
They aren’t always necessary, though. On softer materials, they can be excessive and less forgiving.
Matching the Disc to the Material
Different surfaces respond differently to sanding. Metal heats up. Wood burns. Stone resists. A disc that works well in one situation may struggle in another.
Appropriately sanding a disk requires considering the hardness of the material, the finishing of the surface, and also the amount of material to be actually removed. When these conditions are met, the process of sanding will be under control and not exasperating.
Heat Is Usually the Hidden Issue
Excess heat causes most sanding problems. Discs clog faster, finishes suffer, and surfaces get damaged. This happens when the pressure is too high or the grit choice is wrong. With 150mm sanding discs, steady movement and light pressure usually keep heat under control.
