Safety Precaution About Bench Fitting Shop and Concern to Tools and Equipment Used for

TRADE OF HEAVY VEHICLE MECHANIC

PHASE 2

Module 1

Induction/Customer Care/Bench Fitting/Welding

UNIT: 4

Bench Fitting and Drawing

Table of Contents
1.0 Aims and Objectives 1 Learning Outcome: 1
2.0 Introduction 1 What is a fit in Engineering Terms? 1
3.0 S I System 3
4.0 Derived Units 4
5.0 Basic Drawing Theory 5 Graphical Methods 5 Block Diagrams and Flow Diagrams 5 Schematic Diagrams 5 Circuit Diagrams 5 Detailed Drawings 6 Assembly Drawings 6
6.0 Orthographic Drawing 6 Oblique Views 8 Isometric Projection 8 Perspective Drawings 9
7.0 Scale 9 Dimensioning Drawings 10
8.0 Sections 11
9.0 Circuit Diagrams 12
10.0 Block Diagrams and Flow Diagrams 13
11.0 Hydraulics and Pneumatics 14
12.0 Questions on the Background Notes 15
13.0 Screw Thread Cutting 18 Aims and Objectives 18
14.0 Cutting and Repairing Threads 18 Using a thread pitch gauge 18 1. Preparation and safety 18 2: Step-by-step instruction 22
15.0 Repairing an external thread 23 1. Preparation and safety 23
16.0 Repairing an internal thread 24 1. Preparation and safety 24 Part 2: Step-by-step instruction 25
17.0 Remove and Replace a Stud 26 1. Preparation and safety 26 2: Step-by-step instruction 27
18.0 Using a screw extractor 28 1. Preparation and safety 28 2: Step-by-step instruction 29
1.0 Aims and Objectives

Learning Outcome:

By the end of this unit each apprentice will be able to: • State the function of common workshop tools and equipment and the safety precautions to be observed when using this equipment

• Measure and mark out metal work exercises

• Produce metal work exercises by cutting, drilling, tapping and screw threading

• Drill out and replace pop rivets as part of a metal work exercise

• Re-tap damaged threads on a vehicle component i.e. studs or stud holes

2.0 Introduction

In engineering you are usually concerned with a number of parts or components fitting together to make an assembly, so you must