Hi I have a very simple application which uses a compression spring. There is a slider attached to one end which pushs the spring by 10 mm. After release the spring should throw back a weight of 1 kg(which is the slider weight). Spring Dimensions - OD - 14 ID - 9 What should be my - Closed Length Free length Material .......(it should be non corrosive) Hardness........(should i use a hardened spring. My application is simple but the life is 20-30 years) Coiling direction......(What should be the coiling direction..Left or right...& what effect it makes on the operation) Type of end....(There are many types such as plain, ground end. Actually i am going to load the spring on a shaft of 8 mm. As the slider will slider the pin will enter into a hole in the counterpart. This is deliberately done to avoid any extra operation of spring riveting & ensuring failure proof mechanism) Need Help.