Oil Tempered Chrome Silicon Compression Spring
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This Compression spring, made with 0.120” Oil Tempered
Chrome Silicon wire, requires multiple production steps. The spring is coiled using a unique twist
cut, that allows us to cut the spring with absolutely no cut-off burr
whatsoever. After stress relief, the
spring ends are ground to a minimum 270 degree bearing surface. Even though the blueprint tolerance allows
for a free length variation of +/-0.025”, we coil to a much tighter tolerance,
(+/- 0.005”) in order to maintain a more consistent result in end grinding.
Because the spring is highly stressed, set removal is
necessary. After grinding each spring is
compressed to solid height one time to remove permanent set. Removing set means that the spring is
deflected past the elastic limit, and will not return to the original free
length. The spring will be shorter. To account for this, the spring is
deliberately coiled too long to account for this loss in free length. After set remove, the spring will be at the
target free length. Set removal
introduces beneficial residual stresses into the spring which will allow it to work
a little harder and last a little longer than a typical design would suggest.
After set removal the springs are tumbled to remove
and residual grinding grit and to soften any sharp edges left over from
grinding.
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