Our Surgical Steel Barbells are all 316LVM, NOT the cheaper commercial grade of 316L Surgical Steel body jewelry that you are usually offered by many other company's. Our Barbells are threaded for a precision fit, and for the most part 8 gauge and larger, are all internally threaded, and smaller than 8 gauge is externally threaded, however we can sometimes accommodate special requests, just ask us first. Barbells are the perfect choice for tongue, nipple, and male genital piercings. Bar measurements are taken from between both balls. Barbells come with solid 316LVM Surgical Steel balls.