Fasteners

Table of Contents

Characteristics of a Fastener

• Two Components – threads used to hold them together​ 

  • Male: a threaded bolt.​ 

  • Female: a threaded nut, an alignment hole, a mounting recess, sheet metal slot connector.​
    
• 5 common thread types:​

i. American National (kind of V-thread) - General use​ 

ii. Left-hand - Loosens and tightens opposite to regular.​ 

iii. Square - Ideal thread for power transmission.​ 

iv. Acme - Stronger than the square thread.​ 

v. Buttress - Designed to handle heavy forces in one direction.​ 

i.

iii.

iv.

v.

General Screw Thread Terminology

• Pitch is the distance between adjacent thread forms measured parallel to the thread axis.
• The number of thread forms per inch, N, is the reciprocal of the pitch.
• The major diameter, d, is the largest diameter of a screw thread.
• The minor diameter, d_r, is the smallest diameter of a screw thread.

• Two Thread Standards: American National (Unified) and Metric

  • Metric: designated by pitch.
  • Imperial (Unified): given by the number of threads per inch, N.
• Both metric and imperial have fine and coarse thread series available.

Threads and Data Sheets (Page Link)

Fastener Use Cases

• • Some Fastener use cases are represented in the picture to the right.
  • These cases include:
    • Fasteners to affix a car wheel to the axle or rotor assembly.
    • A rivet to hold a tab on to a soda can.
    • Wood screws to affix deck planks.
    • Etc.

 References

This page is content pulled directly from MTE100, contact the course instructor for details.

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