Synergee barbells are made with world renowned steel These barbells are made with a high tensile strength of 190,000 PSI. Made with the perfect amount of 'whip' and 'flex' for weightlifting, Synergee barbells still have the stiffness needed for heavy powerlifting, Olympic lifting, body building and crushing CrossFit WODs. Each bar is tested for straightness and balance throughout the barbell. Comfort in your grip comes from the knurl. Our goal was to create a full and uniform pattern that is not too aggressive but still gives the maximum grip you need. The knurling on a barbell is ground onto the bar by a specialized machine. The pattern features two sets of diagonal lines, each set going in the opposite direction, so that they form thousands of tiny little diamonds. These diamonds keep your hands from slipping, ensuring your comfort throughout your workout. The inner knurl mark is for powerlifting, while the outer is for Olympic weightlifting.