Plain ends are best suited for large-index, light-duty applications because they tend to cause the spring to bend, decreasing performance reliability.
Using coil guides or shaped platens can help improve performance. Grinding operations provide flat planes, increased stability, and a more uniform load distribution into the spring. Squared ends are preferred on springs with wire diameters of .5 mm or less, an index greater than 12, or low spring rates.
Squared and ground ends are preferred for applications requiring high-duty springs, close tolerances on rate or load, minimal solid height, and reduced buckling.
a constant pitch is maintained for each coil through the end of the wire, without forming any dead coils.
plain-end spring finished with a grinding operation to provide a flat plane.
the pitch of the end coils is reduced so that the end coils touch, forming one dead coil.
squared-end spring finished with a grinding operation to provide a flat plane.