You just offer us your requirements
We will do the next, such as select material, caculate force, produce process.
You will work with more than 20 years experience on extension spring manufacturer. You will get us suggestion on design quickly.We will make them based on your design for your project, and we will not sell to other people.Though spring is very small part of your project, but it is very important.It determines whether the product can be used normally and its service life. So we will take care of that.