[freebeard]

Interesting stuff.

https://en.wikipedia.org/wiki/Lignum_vitae#Uses

It was the traditional wood used for the British police truncheon until recently, due to its density (and strength), combined with the relative softness of wood compared to metal, thereby tending to bruise or stun rather than simply cut the skin.

The belaying pins and deadeyes aboard USS Constitution and many other sailing ships were made from lignum vitae.
....
The aft main shaft strut bearings for USS Nautilus (SSN-571), the world's first nuclear-powered submarine, were composed of this wood. Also, the bearings in the original 1920s turbines of the Conowingo hydroelectric plant on the lower Susquehanna River were made from lignum vitae. The shaft bearings on the horizontal turbines at the Pointe du Bois generating station in Manitoba are made from lignum vitae. Other hydroelectric plant turbine bearings, many of them still in service, were fabricated with lignum vitae and are too numerous to list here.[8]