本文件已被宣布为“稳定”，不再接受货币定期审查。用户负责验证参考资料和持续适用性或技术要求。新技术可能存在。对螺栓进行拉伸和疲劳试验，以确定切割螺栓下封头处的材料流线是否会降低螺栓的完整性。航空航天工业疲劳临界应用中使用的五种不同合金用于制造直径为5/16至«英寸的螺栓。这些螺栓由棒材加工而成，在其头部下产生完全切割的材料流动线。 使用和不使用下封头垫圈的拉伸试验与行业标准疲劳试验一起进行。

This document has been declared "Stabilized" and will no longer be subjected to periodic reviews for currency. Users are responsible for verifying references and continued suitability or technical requirements. New technology may exist.Performed tensile and fatigue tests on bolts to determine if cutting of materials flow lines at the bolt underhead would degrade bolt integrity. Five different alloys used in aerospace industry fatigue critical applications were employed to fabricate 5/16 to « inch diameter bolts. These bolts were machined from bar stock producing fully cut material flow lines under their heads. Tensile testing with and without underhead washers was performed along with industry standard fatigue testing.