These massive heim joints are the best you can buy. They are heat-treated and hard chrome plated to give you a better finish for longer. 
The race is Teflon impregnated nylon for superior durability. 
These rod ends have a 5/8” Shaft with 18tpi. 
The 5/8” bore is the strongest way to make this heim. 
Used on sand rails, a-arms, drag cars, rock crawlers or anywhere a high-quality heim is needed.