SPX vs 3M: Which Sanding Disc System Is Right for Your Workshop?

How a shop should actually test this

Brand arguments are easy to win on paper and hard to trust. The honest way to compare SPX and 3M is to put them on the same panel, in the same hands, at the same stage — then count what changed. Here is the in-house benchmark we run before recommending anything.

Cost per job, not cost per packet

This is the section that actually decides the order. The better question is not which disc has the lowest packet price. It is which disc gives the best cost per job once you include disc life, cut consistency, labour time, dust control, and rework risk.

3M can absolutely earn its price in shops that run its discs hard and value the ecosystem. But a lot of refinishers discover that a well-made ceramic disc at a lower price closes most of the gap on the stages that matter. When SPX changes fewer discs through filler and primer than a cheap standard disc, and costs less than a premium 3M line, the cost-per-job maths usually lands in SPX's favour.

Run your own numbers. Take one job, count the discs used and the minutes spent, and compare. That single test tells you more than any brand claim on this page.