Session 1: Automotive Bolts and Machine Screws
Unit 2: Fasteners
Textual Question-Answers
Check Your Progress
A. Fill in the blanks
1. A fastener is a hardware ………. that mechanically joins or……….two or more objects together.
Ans: device, secures
2. Automotive fasteners are made up of a variety of……………….
Ans: materials
3. A bolt is an externally threaded……………….
Ans: fastener
4. External threads are on the …………….. or screws, and internal threads are on the…………..
Ans: bolts, nuts
5. In India, we use ISO …………..thread.
Ans: metric
B. Multiple choice questions
1. Which automotive fastener(s) is (are) used for holding orconnecting two or more objects in a machine?
(a) Nuts and bolts
(b) Wooden keel
(c) Fibre joint
(d) None of the above
Ans: (a) Nuts and bolts
2. What is the simple, effective diameter of a screw thread?(a) Pitch diameter
(b) Flank
(c) Root
(d) Threaded angle
Ans: (a) Pitch diameter
3. What are the straight sides, which connect the crest and the root, called?
(a) Flank
(b) Root
(c) Minor diameter
(d) Pitch diameter
Ans: (a) Flank
4. Match the following
(a) Eye bolt
(b) Flange bolt
(c) Frame bolt
(d) Hanger bolt
Ans:
(a) Eye bolt
(b) Flange bolt
(c) Frame bolt
(d) Hanger bolt
5. Choose the metal screw on the basis of the head shape shownhere.
Ans: (a)
C. Answer the following questions
1. Describe the importance of bolts.
Ans: Bolts are important fasteners used to hold two or more componentstogether securely. They provide strong and reliable joints, allow easy assemblyand disassembly, and are widely used in automotive machines to withstandvibration and load.
2. What are machine screws?
Ans: Machine screws are threaded fasteners used to join metal parts. Theyare usually screwed into a tapped hole or used with a nut and are commonlyused in machines and automotive assemblies.
3. What is the importance of threads on bolts and machine screws?Ans: Threads help in fastening parts firmly by converting rotational motioninto linear motion. They provide grip, prevent loosening, allow adjustment, and help in carrying loads safely.
4. Differentiate between a bolt and a screw.
Ans: A bolt is used with a nut to fasten parts together, whereas a screw isusually tightened into a threaded hole. Bolts generally require a spanner orwrench, while screws are tightened using a screwdriver.
5. What do you understand by metric thread? Make a profile ofmetric thread and state all the terminologies.
Ans: A metric thread is a standardized ISO thread system used in India, where dimensions are measured in millimetres. The thread angle is 60°. The terminologies of a metric thread are crest, root, flank, major diameter, minor diameter, pitch, pitch diameter, and thread angle.
