S & G Tool Aid 62900 “The Strutter” MacPherson Strut Coil Spring Tool -Sells for a fraction of other types.Each set contains complete instructions and a safety kit. The one piece cold headed bolts are made of chromiumolybdenum alloy steel. The nuts are Grade 5. Do not use on General Motors “A”, “C”, “J” or “X” Body cars. Not for use on any unusually large MacPherson Strut springs which have a coil outside diameter of over 6” or a wire diameter larger than 5/8”.