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WELDED JOINTS 11

11.1 Introduction

Welding is an effective method of making permanent joints between two or more metal parts.

Cast iron, steel and its alloys, brass and copper are the metals that may be welded easily.

Production of leak proof joints that can withstand high pressures and temperatures are made

possible with advanced welding technology. For this reason, welding is fast replacing casting

and forging wherever possible. When compared to riveting, welding is cheaper, stronger and

simpler to execute at site with considerable freedom in design. Hence, it is widely used in ship

building and structural fabrication in place of riveting.

11.2 Welded Joints and Symbols

Basic terms of a welded joint are shown in Fig. 11.1 and the five basic types of joints are shown

in Fig. 11.2.

Base Root opening

metal

Weld

face

Rootface

Fusion

zone

(a)

Bevel angle

Groove or included

angle

Weld size To e

To e

Fusion zone

Weld face

Weld size, leg

Thickness

Throat

Root

(b)

Fig. 11.1 (a) Butt weld (b) Fillet weld

Various categories of welded joints (welds) are characterized by symbols which, in general

are similar to the shape of welds to be made. These symbols are categorised as: