1. Introduction to Fastener Technology
Part 3
An Aerospace Manufacturing Perspective

2. Fasteners in Aviation Permanent Fastening Temporary Fastening
Discussed previously
Temporary Fastening
Threaded
Non-Threaded

3. Temporary Fastening
Threaded
Bolts
Studs
Screws
Non - Threaded

4. Threaded Fasteners Use to hold parts together
Unlike any other fasteners, threaded fasteners are able to move part(s) relative to others

5. Thread Terminology
External (male) thread: Thread cuts outside of the cylindrical body.
Internal (female) thread: Thread cuts inside of the cylindrical body.

6. Thread Terminology Crest – Peak edge of thread
Root – Bottom of thread cut into a cylindrical body
Thread angle – Angle between threads faces

7. Thread Terminology
Major diameter – Largest diameter on an external or internal thread
Minor diameter – Smallest diameter on an external or internal thread

8. Thread Terminology
Pitch – Distance between crests of threads

9. Types of Thread Form
Profile shape of the thread

10. Thread Standard
A metric ISO screw thread is designated by the letter M followed by the value of the nominal diameter D and the pitch P, both expressed in millimeters and separated by the multiplication sign “×”.
Example: M8×1.25

11. Thread Drawings
For simplified representation, use thick and thin continuous lines for representing crests and roots respectively:

12. Bolt Terminology
Bolt is a threaded cylinder with a head

13. Bolt Application

14. Screw Terminology
Screw is similar to bolt, but has a longer thread than a bolt
Bolted joint is usually created by turning a nut; screw is installed by turning it.

15. Screws Application

16. Stud Terminology

17. Stud Application