1. ENGLISH 2 MODUL IV TEKNIK INDUSTRI
Using Hand Tools
Nearly one tenth of industrial accidents are caused by hand tools. There are
two main causes of these accidents :
1) Poor maintenance of tools,
2) Misuse of tools
Maintaining hand tools
Every tools is designed to do a job. If it is properly maintained and looked
after, a tool will work safely. If it is badly maintained, it will no longer do its job
well. In addition, it may become dangerous.
All cutting tools should be kept sharp. A blunt cutting tool can slip on a work
surface. Chisels and punches should be dressed that is, mushrooming on
heads should be ground off ( Fig 23 )
Files should be kept clean. Hammers should be checked for cracks and loose
heads.
Do not use a broken or damaged tool. It may injured somebody.
Misuse of tools
Use the right tool for the right job ( Fig 24 ) Using the wrong tool can cause
injuries.
Tools are bent, chipped and damaged by misuse. Damaged tools are
dangerous.
Section 4

2. Protection on machinery
Machine operators and other workers must be protected against the hazards
of machinery. Barriers and guards are used. They prevent contact with the
moving parts of a machine.
In may workshops, machines are behind barriers. Sometimes, instead of
barriers, white lines are painted on the floor. Each machine has its ‘area’ ( Fig.
26 ) Only the operator or his helpers should be inside the area. Other workers
should stay clear. If they stay clear, they cannot get hurt.
All revolving and moving parts should be covered with guards. Guards are a
kind of protective screen. There are special guards for operating parts such as
cutting edges, drills and tools ( Fig. 27 ) In many cases, guards are specially
designed for certain jobs.
Repair and maintenance of machines
Accidents frequently occur during repair and maintenance. At these times,
guards are removed. Workers may be inside or under a machine. If the
machine starts suddenly, there can be a serious or even a fatal accident.
Special care must therefore be taken by maintenance workers. Before
removing guards, a machine should be ‘isolated’ that is, its electrical power
should be shut off at the mains switch. Guards should be replaced before the
machine is started again. The guards should be correctly fitted and secured.
The grinder or-hand grinding machine.
The grinding wheel is made up of tiny cutting gains or grit. It is designed for
tool grinding, not for grinding soft metals such as brass or aluminum. Soft