Rationale

ASTM A574 imposes a minimum elongation requirement of 10%, I want to add a new supplemental requirement so purchasers may order fasteners with a 12% minimum elongation requirement when they want it. the US Navy imposes this 12% elongation requirement on A574 strength steel socket head cap screws to ensure that they have enough fracture toughness for US Navy use. The US Navy has a high impulse very short duration shock design requirement, and we have found that A574 socket head cap screws need a higher than 10% elongation to reliably survive a shock event.