Keruing (Dipterocarpus spp.) is a heavy, resinous Southeast Asian hardwood group used where toughness and wear resistance matter more than refined workability. Heartwood runs light red-brown through to deeper brown, often darkening noticeably after machining and exposure.
The defining trait is the natural oleo-resin: keruing can feel waxy, it can smell resinous when cut, and that resin influences everything from planing behaviour to finishing and gluing. Straight-grained material can finish cleanly, but interlocked grain is common enough that lower cutting angles and sharp tooling make a real difference.
In the UK it’s best known for demanding, high-abuse roles—lorry and trailer flooring, heavy-duty decking, sleepers and bridge work—where a “pretty” timber would simply get destroyed. Think of keruing as an industrial hardwood: strong, durable enough, and selected because it survives rough service.