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.

• 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.

 References

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

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