NASA Fastener Design Manual 美国宇航局紧固件设计手册 下载链接: https://pan.baidu.com/s/1iNJ1Iye6csqShbige3Omew?pwd=2D3D 提取码: 2D3D

NASA全称National Aeronautics and Space Administration，中文名称叫美国宇航局，针对航空航天产品，NASA制定了自己的标准，其标准不仅包括航空器的设计，还涵盖了最基础的紧固件设计选型。其中，有关紧固件的标准为 NASA Perference Publication 1228 Fastener Design Manual，

NASA 紧固件设计标准主要内容包括Fastener Materials（材料）、Platings and Coatings（镀层和涂层）、
Thread Lubricants（螺纹润滑）、Corrosion（腐蚀）、Locking Methods（防松措施）、Washers（垫片）、Inserts（嵌件）、Threads（螺纹）、Fatigue-Resistant Bolts（耐磨损螺栓） 、Fastener Torque（拧紧扭矩）、Design Criteria（设计标准），下面是部分截屏，全文参见上面的下载链接。

特别注意，NASA 紧固件设计手册 针对开口弹簧垫圈做了特别说明，具体如下：

The typical helical spring washer shown in figure 14 is made of slightly trapezoidal wire formed into a helix of one coil so
that the free height is approximately twice the thickness of the washer cross section. They are usually made of hardened carbon steel, but they are also available in aluminum, silicon,brome,phosphor-bronze, stainless steel, and K-Monel.

The lockwasher serves as a spring while the bolt is being tightened. However, the washer is normally flat by the time the bolt is fully torqued. At this time it is equivalent to a solid flat washer, and its locking ability is nonexistent. In summary, a Iockwasher of this type is useless for locking.

当螺栓拧紧后，开口弹簧垫圈相当于弹簧。然而，当螺栓按规定扭矩拧紧后，开口弹簧垫圈就会变平，此时它相当于一个坚固的平垫圈，其锁定能力（防松能力）是不存在的。总的来说， 这种类型的锁止器对于锁定是无用的。

参考文献：https://ntrs.nasa.gov/citations/19900009424