METALWORK HAND TOOLS – II

 METAL WORK- HAND TOOL- Cutting and Driving tools

CUTTING TOOLS

Cutting tools are tools used for cutting materials by sawing, filing, chiseling, and scraping.

Cutting tools include the following: 

•             Files

•             Hacksaw

•             Chisel

•             Scraper

•             Hacksaw

The hacksaw consists of two parts: the frame and the blade. It is used mainly for cutting metals in the metal workshop. We have (i) the adjustable hacksaw (accommodates different blades) (ii) the tubular hacksaw (Has a fixed frame) (iii) the junior hacksaw (For cutting thin sheets)

•             Files

Files are used in forming metals to shape, by the principle of bit-by-bit removal. Files are used for finishing jobs to the required sizes and shapes, after they have been previously cut, using either a chisel or a hacksaw. Files are commonly made from high carbon steel (hardened and tempered). Their length, cross-sections, shapes, grade, areas of cut, and the nature of their cutting teeth, classify files.

Grade selection 

•             Rough grade: Used for heavy cuts.

•             Bastard grade: Used for medium cuts.

•             Second grade: Used for light cuts.

•             Smooth grade: Used for finish cuts.

1.          Dead smooth cut: Used for light-grade finish cuts.

 Types

1.     Flat file: Used to obtain flat surfaces.

2.     Hand file: Used to obtain flat surfaces.

•      Round file: Used for forming small radii, and for opening out round holes. 

•    Half-round file: Used for filing curves of all shapes. It is usually double-cut.

•    Triangular file: Used for forming dovetail joints to shape and open up triangular holes and awkward corners.

•   Knife-edge file: Used for forming small V-grooves to shape.

•   Square file: Used for filing rectangular holes, narrow slots, and grooves, and for the finishing of square edges.

  Methods of filing

•    Across and from left to right

•    Across and from right to left

•   Draw filing

Evaluation 

1.   State 3 key points about the use of chisel.

2.  Mention 7 types of chisel and their uses

 Chisel 

Chisels are mainly chipping tools used for shaping metals, whereas finishing by other means, such as filing, cannot be carried out. Chisels are made from high carbon steel (hardened and tempered) 

 Types of chisel

Flat chisel: Used for general work such as:

1.   Leveling metal surfaces

2.  Removing rivets, screws, and bolt heads

3.  Rough-cutting sheet metals, and 

4.    Cutting off excess metal after drilling 

Cross-cut chisel: Used for:

1.   Cutting keyways on shafts and in holes

2.  Cutting spines and

3 Cutting slots 

Round-nose chisel: Used for:

1.   Cutting oil grooves in bearings and 
2.   Cutting V-shaped grooves.

Diamond point Chisel: Used for:

1.  Cutting Vee grooves, and

2  Cutting oil well bearings: 

Evaluation 

1.   State 5 key points about the use of chisel.
2.  Mention 4 types of chisel and their uses   

 Scraper 

Scrapers are used for removing imperfections from a surface that has been previously worked on. Scrapers are made from medium carbon steel (hardened and tempered)

Flat scraper: Used for making a surface accurately flat, after it has either been machined or filed. It requires high-level skill to use

Half-round scraper: Used for removing high spots on curved surfaces such as holes, bearings, and large bores.

Triangular scraper: Used in awkward corners, where the use of the other scrapers proves difficult 

Evaluation 

1.          Outline the procedure for carrying out scraping work

2.          Mention 3 types of scraper and their uses 

DRIVING TOOLS

Driving tools are tools used for moving objects into metals through hammering, punching, or screw driving.

Driving tools are tools include the following:

1.          Hammers

2.          Punches 

3.          Screwdrivers 

HAMMERS

Hammers are the most commonly used of all tools. They consist of a metal head and a wooden handle.

Types of hammer

•             Ball Pein Hammer: Used for riveting conical end rivets, while the other flat end is for striking.

•             Cross Pein Hammer: Used for riveting in awkward places and flat end used for striking 

•             Straight Pein Hammer: Used for riveting in Vee-grooves.

•             Special Hammers (Mallets): Used when steelhead may be too strong for the job. They are made of lead, copper, rawhide, wood, plastic or rubber. They are called Mallet 

PUNCHES 

Punches are driving tools. They are used for punching holes in steel metal and driving out rivets, tapered pins, or dowels from holes. 

•             Pin Punches: They are used for driving dowel pins, and holding shafts and clubs together.

•             Round Punches: They are useful when a round sleeve or shaft has to be removed from a hole

•             Square Punches: They are useful where a square bar sleeve has to be removed from a hole in which it is. It must be noted that all punches are aided by hammer strikes to achieve their goal. 

SCREWDRIVERS

Screwdrivers are used for fixing or removing screws by their heads. This is done using the blade of the screwdriver. Screwdrivers are made from carbon steel (hardened and tempered)

Types of screwdriver

1.          Flat screwdrivers

2.          Star screwdrivers

3.          Ratchet screwdrivers

4.          Allen key

General Evaluation

1.          Define driving tools 

2.          State 8 driving tools and their uses.