These are made from high grade stainless steel, beware of cheap imitations they will strip in the head which will damage the metal sleeve. Also beware of the Type of washer... you would think any washer would suffice... Not So, these washers made from special epm material with a fiber insert in the middle, if you use some other washer, it will split & become useless, it will also give you a different sound & feel when hitting the club.