endurance during testing conditions, the spanner heads have polished finishing for strength, and to protect them against corrosion. as well as static and fatigue mechanical performance, wear and corrosion resistance testing. Very durable thanks to industrial-grade chromium-vanadium steel of the highest quality. Manufactured from chrome plated steel and drop forged with polished heads, making. If you have any questions, please feel free to contact us, we will help you at any time and contact you within 24 hours.