Hand tools are the tools which are used by human in a workshop for various electrical installation related works and also for various maintenance works.
Types of hand tools
1. Screw driver
A hand tool used to fix and remove screws. Used in assembling work and maintenance work. Available in three main types:
a) Flat type – Point of the screw driver is flat shape used for straight slot screws.
b) Pozidriv type (Philips type) - Point of the screw driver is special shape (x shape) to match with the slot in pozidriv slot screw. Used for Pozidriv slot screws.
c) Offset screw driver – Designed for use in confined areas where it is impossible to use a standard screw driver.
A hand tool used for delivering blows (force) in chipping using chisel, bending, straightening and other operations. Hammers are forged from high carbon steel. Hammer sizes are specified by their weight. Main types of hammers are:
a) Ball pein hammer – Most commonly used hammer. Consists of flat face for general work and ball pein for peining or riveting.
b) Cross pein hammer – Used for sheet metal forming
c) Straight pein hammer – Used for sheet metal work
4. Tape measure
The most common tape measures are 12 feet, 25 feet, or 100 feet in length.
Portable power tools suitable for drilling walls
• Hand drilling machine
Manually hand operated drilling machine. Used for rough and smaller diameter hole drilling.(Up to about 5mm dia.) Mostly used to drill soft materials.
• Portable electric Drilling machine
Electrically operated hand drill. Used for rough and small diameter hole drilling (up to about 18mm dia.)Spindle is driven by the electric motor and feeding of drill is done by human hand. Can drill metals also.
• Hammer drill
The cutting tool used on a drilling machine is known as a Drill bit ( Drill). The most common type of drill is Twist Drill.
Twist drill is consists of 2 main parts:
i) Body – A cylindrical part make with 2 helical flutes to provide the cutting lips and cutting point to remove the chips. To reduce the friction of the body and the point against the walls of the hole and for better guiding of the tool, only a part of the cylindrical surface is left project and form what are called the lands.
ii) Shank – The part of the drill which to the machine. Depend on the method of applied to securing the drill, the shank available as
a) Straight or Cylindrical type – Available as drills which are less than 12.7mm in diameter. When fixing the straight shank drills to a drilling machine a Drill chuck or a Collet chuck is used.
b) Taper Shank – Consists of standard Morse taper shank. Available as drills which are more than 12.7mm in diameter. When fixing the taper shank drills to a drilling machine the Morse tapered spindle hole or Morse tapered sleeve is used.
Types of twist drill
• General purpose drill – a drill with standard helix angle or Rake angle of 60°. Used to drill mild steel, cooper alloy etc.
• Slow helix drill – A drill with larger helix angle , Used to drill hard materials
• Quick helix angle - A drill with smaller helix angle , Used to drill soft materials
• Straight flute drill – Flute which take straight shape. Used to drill very soft material
• Flat drill – A drill without a point. Used to drill sheet metal