Metalworking
Practical Action
Blacksmithing
Forging or blacksmithing is one of the oldest methods of making objects from metal. An
outline of blacksmithing is described in the Practical Action Technical Brief Blacksmithing.
The main item required is a forge where the metal can be heated. The other basic
requirements are an anvil, a hammer, and some tools to hold the metal while it is being
worked.
An example of the type of product produced is described in the Practical Action Technical
Brief The Donkey Plough.
Tinsmithing / Sheet metalwork
Sheet metal work is the process of producing such objects as buckets, boxes, tanks, drums,
cupboards, desks, ducting, vehicle bodies, etc, from sheet metal. Traditionally tin was
commonly used which gave
its name to the process but
now steel is often used. In
developing countries scrap
car bodies are a common
source of material.
Tinplate, used for making
articles such as funnels,
where economy of material
combined with ease of
working are required, is
usually in the thickness
range of 0.3 to 0.8 mm.
Thickness of galvanized
steel in common use range
from about 0.7 to 2.5 mm.
Aluminium, copper, brass
and uncoated steel sheet are
used in thicknesses from
0.3 to 3 mm.
Figure 2: Examples of the some of the tin products
produced by the trainers who carry out training in
tinsmithing by Practical Action Bangladesh. Photo
credit: Practical Action/Zul
Metal folding and bending
The simplest approach to use a hammer and anvil to produce the shapes you want. Various
designs of low cost folding and bending equipment have been developed by Apt Design &
Development based on practical experience.
Folding machines work on a variety of
principles. For general purposes, such as
folding sheet metal to make a box, a box-and-
pan type machine is convenient. This consists
of a flat table, a clamp to hold down the sheet,
and an edge that folds up or down to force over
the projecting edge of the sheet. Various
configurations are used to allow the bending of
intricate shapes such as internally flanged
boxes. Another form of bending machine, an
angle bender, works by forcing the sheet into a
V notch by the action of a blade applied by
hand lever or by power. These machines are less
versatile but once set up for a particular job,
can be quicker in use than a folding machine.
Figure 3: A Jenny for sheet metal work.
Designed by Graham Saunders.
Illustration by Graham Sounders
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