From the gutter dwellers at Cutlery Corner
"...the knife handles are made from Delrin, the stuff bowling balls are made of..." Todd Boone
Delrin is a Polyoxymethylene trademarked by DuPont and is not used in the manufacture of bowling balls. It is highly doubtful that Chinese manufacturers are actually using Delrin for anything let alone bowling balls, but far more likely substituting any number of their knockoff plastics, just like they do with Teflon; mixing a home brew of low grade PTFE's and labeling them Teflon.
Delrin is used for knife handles, so at least they got that correct, but as usual the carnival barkers have to embellish with lies in order to make their potmetal products appear more appealing and valuable.