1 / 24

Bolts and Fasteners

Bolts and Fasteners. Fasteners are manufactured in a wide range of materials: common steel titanium plastic and other exotic materials. Bolt Identification Bolts are identified by 3 measurements:. Diameter Measured across the threaded area with a caliper or micrometer. Length

Télécharger la présentation

Bolts and Fasteners

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Bolts and Fasteners • Fasteners are manufactured in a wide range of materials: • common steel • titanium • plastic • and other exotic materials.

  2. Bolt Identification Bolts are identified by 3 measurements: • Diameter • Measured across the threaded area with a caliper or micrometer. • Length • Measured from the bottom of the head to the end of the shank • Thread Pitch • (Discussed on the next slide)

  3. Thread Pitch • Thread pitch (English system) • The number of threads per inch • Thread pitch (Metric system) • The distance in millimeters between two adjacent threads

  4. Measuring Thread Pitch – Using a Thread Pitch Guage.

  5. Bolt Grade Markings A bolt’s grade is a measurement of its Tensile Strength • U.S.C. (inch) bolts • Radial lines on the head of the bolt correspond to tensile strength. • More lines represent increasing strength. • Count the number of lines and add 2 to determine the grade of the bolt (ex. 3 lines indicates a Grade 5 bolt).

  6. Bolt Grade Markings A bolt’s grade is a measurement of its Tensile Strength • Metric bolts • Property class numbers on the head of the bolt correspond to tensile strength and yield strength. • The Property Class is expressed with 2 numbers (ex. 10.9). • The 1st number represents the Tensile strength of the bolt (ex. 10 = 1,000 MPa). • The 2nd number represents the percentage rating of the bolt’s Yield strength (ex. 9 = 90% of 1,000 MPa). • Increasing numbers represent increasing strength.

  7. USC Bolt Identification Example • An Imperial size bolt that is identified as 3/8" x 2" x 24: • Has a shank diameter of 3/8 inch. • Is 2 inches long from the bottom of the head to the end of the shank. • Has 24 threads per inch.

  8. Metric Bolt Identification Example • A metric size bolt that is identified as • 6mm x 30mm x 1.00mm: • Has a shank diameter of 6 millimeters. • Is 30 millimeters long from the bottom of the head to the end of the shank. • Has a distance of 1.00 millimeters between its threads.

  9. Key Terms

  10. Torque-To-Yield Bolts • A torque-to-yield bolt must be tightened to its Yield Strength. This means tightening the bolt to a specific torque and then a specified number of degrees (Using a Torque Angle Gauge). • Some Head Bolts are Torque-To-Yield Bolts

  11. Unified Thread Standard The Unified Thread Standard defines a standard thread form and series used commonly in the United States and Canada. Example: • UNC – Unified National Course Thread • UNF – Unified National Fine Thread • A 3/8” UNC bolt has 16 Threads Per Inch • A 3/8” UNF bolt has 24 Threads Per Inch

  12. Unified Thread Standard Other UTS designations include: • UNEF – Unified National Extra Fine • UNPT – Unified National Pipe Thread (used commonly in plumbing and other areas where the threads are used to seal off a liquid) • Oil Drain Plug • Pinion Nut • Engine Coolant Temperature Sensor • Other pipe like things

  13. Thread Sealers and Lockers Thread Sealer Thread Locker • Thread sealers prevent leaks around bolt threads. • Thread lockers such as Locktite prevent bolts from coming loose due to vibrations.

  14. Anti-seize Compound • Anti-seize prevents bolts from getting stuck due to rust and corrosion.

  15. Thread Repair • Threads can get damaged on bolts and nuts from excessive use and from misuse. • A Tap & Die set is designed to create or repair threads.

  16. Tap & Die • A Tap cuts internal threads. • A Die cuts external threads.

  17. Tap & Die Sets There are 3 common types of Taps used by machinists today: • Bottoming Tap - The tap illustrated at the left of the image has a continuous cutting edge with almost no taper. A bottoming tap is used on holes that already have threads.

  18. Tap & Die Sets • Intermediate Tap - The tap illustrated in the middle of the image has tapered cutting edges, which assist in aligning and starting the tap into an untapped hole

  19. Tap & Die Sets • Taper Tap - The small tap illustrated at the bottom of the image is similar to a plug tap but has a more pronounced taper to the cutting edges. This feature gives the taper tap a very gradual cutting action that is less aggressive than that of the bottoming tap.

  20. Bolt Extraction • Broken bolts have to be removed before the threads can be repaired. • Bolt Extractors are tools designed to remove broken bolts.

More Related