1. Compression springs are the easiest type to make, can be made more rapidly and accurately then other type. Should be preferenced to other type of springs as well.
2. Avoid using open ends or open ends ground. Such springs usually tangle when shipped. They also buckle when deflected.
3. Use closed ends not ground whenever possible, expecially on light wire, or where a large spring index prevails.
4. Use closed ends ground and state degree of squareness on important springs and on those used under diaphragms or in regulator valves, or where buckling might occur.
5. Use conical springs when a short, solid height is needed and to reduce buckling and surging.
6. Avoid using conical, barrel shaped, or other special shapes, including tangs on the ends,, when a standard helical spring could be used.
7. Design springs with a reasonably safe stress when compressed solid so that they mabe be adaptable to other installations.
8. Hand-do not specifity coiling right or left hand if it is not important. Specifiy right hand if it must be threaded onto a bolt. If a spring is used inside another one spring should be wound left and the other spring should be wound right. This prevents meshing of the coils.
9. There are four basic types of compression spring ends as shown above. The particular type of ends specified affect the pitch, solid height, number of active and total coils, free length and seating characteristics of the spring.
10. Specify unusual conditions such as high or low temperatures, corrosive surroundings, impact force and fatigue life or number of cycles of deflection desired on drawings of springs.
Graphic layout of Specificiations for Drawbar Springs