SUBJECT: BASIC TECHNOLOGY
TERM: 3RD TERM
- MELROSE, Basic Science and Technology Book 1
- NERDC, Basic Technology for JSS, Book 1
TOPIC: METAL WORK- HAND TOOL- Holding Devices
In order to work safely and conveniently on any work piece, it needs firmly secured. The devices used for holding these work piece firmly are called holding vices.
Holding devices include the following:
Vices are used for holding objects rigidly in position, so that desired operations can be carried out. Vices are of various sizes, shapes and types.
The bench vice is used for all types of heavy work, like filing, chipping and sawing. It is fastened to the bench, near its edge, with bolts and nuts. It has two separate jaws that ensure a firm grip on a work piece.
The machine vice is commonly used on drilling, milling and shaping machines. The jaws are left unseparated, so as not to leave any work an already finished surface.
The hand vice is used for holding small work piece that cannot be handled conveniently by the bench vice because of their small size.
Blacksmiths use the leg vice. It is used for holding work piece that require heavy blows to bend. The vice is therefore made from wrought iron that has the capacity to absorb heavy blows without being damaged. 8
Clamps are also holding devices, used for holding work pieces for various jobs. Clamps are mainly of three types.
- Toolmaker’s clamp: The toolmaker’s clamp is used for holding metal in drilling operations, as well as for securing jobs on angle plates for marking out. It has two long screws one for tightening, and the other for locking.
- G-Clamp: The “G” Clamp is used by metalworkers for securing long work pieces to the table of a drilling machine, for drilling operations. It is used in conjunction with an angle plate to secure big jobs when marking out.
Pliers are useful general purpose holding tool.
TYPES OF PLIERS
- Long nose pliers
- Flat nose pliers
- Round nose pliers
- Outline the procedure for using clamps
- Mention 4 types of pliers
GENERAL CARE OF HANDTOOLS
Metal work hand tools need careful handling during and after use. They should also be kept or stored properly to remain accurate, and to serve in the future. The following guidelines will help you to care for the workshop tools:
- Use the right tool for the right operation. Using the wrong can damage the tool and the work. It can also cause injury.
- After use, clean the tool before it is stored away.
- Store tools in an orderly manner. There are racks for drills, chisels and spanners. Tool s should be arranged in proper order, as this will make it easy to pick them up for use.
- Store tools away from pathways, so that they do not cause obstruction to free movement.
- Avoid keeping them in a damp place, as keeping them in damp place will them to rust and get damaged.
- State 5 general care of hand-tools.
- State 3 types of holding device.
- State and explain 4 types of vice.
- State 3 types of pliers and their uses.
Read about MORE ON HAND TOOLS.
NERDC- BASIC TECHNOLOGY BOOK 1, page
- The devices used to keep jobs in the workshop firm to the work bench are called___ (a) cutting tools (b) driving tools (c) holding tools (d) marking out tools
- The following are examples of holding devices except___ (a) vices (b) clamps (c) pliers (d) odd leg caliper
- The type of vice, which is commonly used on drilling, milling and shaping machines is called_____ (a) bench (b) machine (c) leg (d) hand
- Which of the following is not a type of clamp? (a) Drill (b) Pliers (c) Toolmaker’s (d) G-Clamp
- Which of the following is used for holding metal in drilling operations, as well as for securing jobs on angle plates for marking out (a) Drill (b) Pliers (c) Toolmaker’s (d) G-Clamp
- State the general care of hand tools.
- State 3 types of work holding devices and their uses