SouthOrd's 0.031 inch thick SouthOrd MAX Lock Picks are manufactured of High Yield Stainless Steel, the strongest and most durable stainless available, and feature lightweight ergonomic ABS handles. Type 301 High Yield material is often used for applications requiring extra high strength. It is much harder than Full Hard material, having a minimum tensile strength of 270,000 PSI, compared to 185,000 PSI for Full Hard.