PEEK is a general term, an abbreviation, for the polayaryletherketone (PAEK) polymer [whose full name is poly(oxy-1,4-phenyleneoxy-1,4-phenylenecarbonyl-1,4-phenylene) ] and whose molecular backbone structure is defined by the repeat unit below.

VICTREX PEEK 450G is a specific grade of PEEK polymer, a unique grade which is only made by Victrex and which has a specific range of molecular weight.  The molecular weight defines the bulk properties of the PEEK 450G polymer, including its stiffness, strength, toughness, crystallinity and melt processing behaviour.