1、铆钉背距
... back pitch 背节距 back pitch 铆钉背距 back plan 底视图 ...
2、背节距
... back piece 背材 back pitch 背节距 back pitch 铆钉背距 ...
3、后节距
... back lock 反位锁... back pitch 后节距... back resistance 反向电阻...
4、横节距
... 平曲线横净距 lateral clear distance of horizontal curve 横节距（铆接） back pitch (平曲线)横净距 lateral clear distance of curve ...