Q: Hoping you can help me out. This seems like a technical screw that you may have knowledge on. My customer asked me for a 1/2″-13 x 2″ Long screw FF-S-86 TY IV, QQ-N-281. I’m clear on the size but what does the rest mean? I don’t even know the screw or material?
A: Your customer is asking you for a screw per Military Specification FF-S-86. FF-S-86 covers various types of socket head cap screw fasteners. The TY IV means they want the style listed in the specification as Type IV which is a flat head socket cap screw with a standard 82deg angle. Next QQ-N-281 is a specification that refers to the material Monel 400. This is important to note because it means that the Monel 400 used to make your bolt must adhere to the requirements of specification QQ-N-281. Therefore, your customer requires a Flat Head Socket Cap Screw size 1/2″-13 x 2″ long made out of Monel 400.