Bar Flex is a Grade 304 austenitic stainless steel helical wire that has many properties that makes it an ideal reinforcement material. Unlike similar diameter material, Bar Flex is flexible enough to allow natural movement in masonry, while being strong enough to resist abnormal loads. In addition, with its small diameter, it is the ideal material for reinforcing cracked masonry ("crack stitching") such as in places where lintels have failed, or where differential movement in walls has caused separation.
Because of features introduced during the manufacturing process, Bar Flex is a material that is both hard and soft (the fins are work hardened to a very high level whilst the core remains relatively soft) and simultaneously in tension and compression (the hardened fins are in tension and the soft core is in compression). As a result, the tensile strength of the base material is more than doubled during the manufacturing process. The deformation of the fins makes the bonding characteristics of the Bar Flex, far superior to alternative standard reinforcing materials.