When developing and manufacturing a spring, it is critical to consider the inner and outer diameters of the spring, as well as its free length and solid height. You should also think about the spring materials, since they will impact the size of your spring. Finally, you need to consider how you will use the spring when it is completed. There are several different methods used to select the correct-size spring for your application. The first thing to do is measure each spring in the same condition so that there are no variances due to quality control issues or handling during development. Next, find the proper code for the spring requirements. These codes will help you identify which spring is right for your application. The first code you will need is the JIS code. This code indicates which country's standards were followed in producing the spring. Each country has its own set of standards for springs, so be sure to check with your supplier to make sure they follow the correct standards. After checking the JIS code, you can look up the proper name for the spring using the B number. This number is found on most any type of spring catalog. It will tell you what material the spring is made from and its dimensions. For example, if you were to look up number B 801 in a catalog, you would know that this is a Japanese IDON wire spring with a diameter of 1/4 inch.