Chapter 8 PowerPoint

Define these Technical Terms using the textbook:

1. adhesive

2. bolt tightening sequence

3. cotter pin

4. criss-cross pattern

5. gasket

6. screw extractor

7. sealer

8. torque specification

9. torque wrench

Answer these discussion questions using the textbook:

1. Describe the need for torquing bolts and fasteners.

Read the chapter summary below:

■ Fasteners are devices that hold the parts of a vehicle together.

■ When a high-quality bolt is threaded into a part without a nut, it can also be called a cap screw.

■ Bolt size is a measurement of the outside diameter of the bolt threads.

■ Tensile strength, or grade, refers to the amount of pull or stretch a fastener can withstand before breaking.

■ A flat washer increases the clamping surface under the fastener.

■ A lock washer prevents the bolt or nut from becoming loose under stress and vibration.

■ It is very important that bolts and nuts are torqued properly.

■ Torque specifications are tightening values given by the vehicle manufacturer.

■ Generally, tightening a group of fasteners on a part follows a criss cross pattern.

■ A torque wrench measures the twisting force applied when tightening a threaded fastener.

■ A tap is a threaded tool for cutting internal threads in holes. A die cuts external threads.

■ Machine screws are similar to bolts, but they normally have screw driver type heads.

■ Numerous types of non-threaded fasteners, such as snap rings, clips, and adhesives, are utilized in the assembly of a vehicle.

■ Adhesives are widely used on most vehicles.

■ A gasket is a soft, flexible material placed between stationary parts to prevent leakage.

■ RTV sealer, also called silicone sealer, cures in the presence of air. It is used to form a rubber-like gasket on thin, flexible flanges.

■ Seals prevent leakage between a stationary part and a moving part.