2013 巻 (2013) 58 号 p. 49-77
In coil spring manufacturing process, the low temperature annealing after coiling is an important process. It is known that the dimension of coil spring varies after the low temperature annealing. We measured systematically this dimensional change. After the low temperature annealing, the coil diameter of SWP-B (SW-C, SWOSC-V) spring becomes smaller, and that of stainless steel wire (SUS304WPB) becomes larger. The low temperature annealing is also important from the stand point of sag resistance. When we do not apply this annealing, we get large sag in a clamping test. The value is more than 10 times compared with normal processing. Don't miss low temperature annealing process, in order to obtain a good spring.