"螺旋距"用英语怎么说？

就是螺距，英文是pitch。

注：pitch,
The distance between two corresponding points on adjacent screw threads or gear teeth.
螺距：两个相对应的点或相邻的螺钉之间的距离

spiral distance

helix distance

thread pitch

Pitch of screw
http://babelfish.altavista.com/tr