What is the purpose of brass liners over the jaws of a bench vise?

The purpose of brass liners over the jaws of a bench vise is primarily to prevent damage to the workpiece being clamped. Brass is a softer material compared to steel, which means that when clamping an item, the brass liners can absorb some of the impact and pressure without marking or denting the surface of the workpiece. This is especially important when working with delicate or finished items where preserving surface integrity is critical.

While other purposes such as improving grip or facilitating quicker adjustments could be considered advantageous features of bench vises in general, the main intention of using brass liners is focused on protecting the work from physical damage during the clamping process. This protective function ensures that the workpiece remains in good condition, which is vital for quality results in various projects that require precision and care.