NABTEB Metal Work Syllabus For 2022

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difference between ”˜line’ and ”˜end’ measurement and the use of measuring instrument in bench work.

2. Maintain and describe various types of instrument used in metal work, their various functions, their grades, applications and state the safety precautions to be observed.
3. Compare the limits of accuracyperform marking out exercise on plain surfaces.
4. Sketch the bench vice,explain its clamping power and demonstrate the technique holding work in the vice.
5. Select and install hawksaw correctly.

copper, tin, zinc, aluminium and aluminium alloy brass (metal muntz, phosphorus, bronze and lead).

2. The difference between ”˜line’ and ”˜end’ measurement.
3. The functions and application ofinstrument used inmetal work.
4. The use of datumpoints, datum lines and datum faces in marking out.
5. Essential features and use of tools and instruments.a. micrometer
   2. vernier caliper
   3. combination set etc.
6. Maintenance of tools/instrument

– limits of accuracy.

7. Marking out exerciseson plain surfaces.
8. Types of files, grades and applications.
9. Classification of filesand their composition.
10. Filling of metals togiven specificationsusing either:
11. Cut a piece of metal toa given specification to be filed using different types of files.
12. Sketching of a bench vice.
13. Demonstrate the technique of holding work in the vice for

2. Carry out maintenance work on theinstruments.
3. Explain the workingprinciples of:
   a. Micrometer;
   2. Vernier caliper
   3. Vernier height gauge
   4. Combination set.
4. Sketch various tools and instruments used.
5. Types of files should include: flat, square, half round, triangular, warding, mill and rasp.
6. Demonstrate how all the tools mentioned are used in the workshop.

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various exercise with a

piece of metal.

14. Description of thefunctions.
15. Functions of the parts.
16. Hammers and mallets.
17. Chisels.
18. Punches
19. Scrapers.
20. Power hacksaw
21. Safety precautions
22. Types of hacksaw
23. Explain and sketchvarious tools used inthe workshop.
24. Types of hacksawblades their pitches andapplication.
25. Selection andinstallation of blades.
26. Cutting process using:
    1. adjustable hacksaw
    2. junior hacksaw
    3. piercing saw etc.

4.

Drills and Drilling

1. Identify, set up, operate anddescribe with sketches, the various types of drilling machine, their main features, where they are best suited and safety precautions to be observed when using them.
2. Perform drilling operation, state the cause and remedy of

1. Types of drilling machine and their operations.
2. Sharpening of drills bits.
3. Sketches and explanation of various drills e.g. Twist drill (taper shank, parallel and jobbers drill and their relative merits).
4. Effects of faults in twist drill bits e.g.
   1. point angle too acute.
   2. Point angle too obtuse.
   3. Cutting edges at unequal angles.
   4. Insufficient lip

1. Setting up drilling machine should include:
   1. Change of spindlespeed.
   2. adjustment ofdrilling table to the required height and angle, holding of works on drilling table using appropriate clamping device.
   3. Install the drill bit in chuck
2. Cut a piece of metal to a given specifications and perform drilling operations on holes given.
3. Drill and ream holes on

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drilling faults.

3. Explain thepurpose of reaming and reamers to given specification by hand and machine method.
4. Calculate spindle, therevolution or cutting speed for specific size of drill.

clearance. e. Excessive lip

clearance.
5. Calculation of spindle

formulae: N = 1000S πd

Πd 1000

S =

Where
S = cutting speed (m/min)
N = revolution/minute d = diameter of drill (mm)
Ï€ = 3,142

6. Causes and remedy of drilling faults e.g.
   1. Drill breaking.
   2. Drill coloured blue
   3. Walls of drill holeleft rough.
   4. Chipped cuttinglips.
7. Safety precautions.
8. Drilling operations e.g.
9. Types of hand andmachine reamers.
10. Reaming and mode ofoperations.
11. Reaming tospecifications.

metals and other

engineering materials.

4. Calculate someproblems in spindle revolution or cutting speed on particular size of drill.
5. Carry out different drilling operations base on specified materials and measurements.

5.

Fastenings

1. State and explain the meaning of

tapping size or tapping drill, its functions, precaution to be taken when tapping on bench and estimate its

1. Forms of threads and application.
2. Functions of taps.
3. Sketching variousforms and the meaning

of the following:

1. The 150 metric thread.
2. The unified thread.
3. Whitworth andBritish fine thread.
4. British Association

1. Demonstrate the application of various forms of screw thread, rivet and cut screws by hand.
2. Draw and perform an exercise on how to apply rivets and solve a problem involving allowance.

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value.

2. Sketch thethread forms, state their application, their operational sequence and cut internal thread external thread by hand method.
3. Describe and differentiatetypes of rivets, sketch rivet set, state their uses, calculate the diameter and rivets metals together.

(BA) thread.

5. Square thread.
6. Acme thread
7. Butress thread.

4. Functions and sketches of:
   1. taps (taper tap, second tap, plug)
   2. tap wrench
   3. die and die stock
5. Operation sequence
6. Cutting and precautionto be observed.
7. Sketching and rivetingexercises.
8. Calculation of tappingvalue in any situation using formulae T = D-P where T = Tapping diameter D = thread top diameter, P = Pitch.
9. Types of rivets e.g. snap and pan heads, mushroom and counter- sunk head, flat head, pop rivet etc.
10. Calculation of diameter and allowance of rivet.

6.

Tolerance and Fit

1. Explain the importance oftolerance and fit in engineering production and describe briefly the I.S.O.
2. Differentiate betweentolerance and fits, calculate the amount of tolerance and types of fit in given situations.

1. The difference between limits, fits, nominal size and tolerance.
2. Importance of fits and tolerance engineering production.
3. Calculation of fits and tolerance

Do some calculation on tolerance and fit based on given specifications.

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7.

Production

1. Determine layoutprocedures from working drawing of simple engineering components or tools.
2. Mark out only given benchwork and produce any type of centre lathe to given specification.
3. Carry out simple precision fitting project.

1. Layout procedures of a working drawing e.g.
   1. Open ended spanner
   2. Engineer’s try square
   3. Tools makers clamp
   4. Plate bracket or gusset (involvingwounds, angles,holes).
   5. Centre square.
2. Methods of marking out for given bench work with the use of centre dot, punch, scribing block or measurement transfer.
3. Production of some mentioned items.
4. Simple precision fitting projects e.g. Hexagonal mild, steel bar making push fir through a mild steel plate.

1. Produce simple engineering components on the bench based specifications.
2. Carry out some precision fitting project in the workshop.

8.

Lathe and Lathe Work

1. Identify, explainand describe the working principles, essential features, functions of a centre lathe and its accessories, differentiate between centre lathe and capstan lathe in terms of their functions.
2. State and name

1. Features of a centre lathe e.g. lathe bed, head stock, tail stock, saddle or carriage etc.
2. Function
3. Working principles.
4. Types of cutting fluids.
5. Tools involved andtheir functions.
6. The differencebetweens centre latheand capstan lathe.
7. Types of cutting fluidand safety.
8. Sketching of commontools e.g. buttbrazed tool, typed tool, bit and holder ”“ functions and

1. Explain the essential features of a lathe machine.
2. Carry out basic operations e.g. Facing, Turning (Plain), Stepped Turning, Knurling etc.
3. Tool description should include tool materials e.g. Plain carbon steel, high speed steel, stellite, cemented carbide diamond.

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types of cutting fluids used for lathe turning operations, their composition, their purposes and outline safety precautions involved.

3. Sketch, explain and describe

common tools, functions of tools, angle rake, clearance and state the values for different metals to be machined.

values.
9. Functions of centre

lathe accessories e.g. Catch or driving plate, face plate, lathe dog, or carrier, lathe centre, fixed and traveling steadies.

9.

Heat Treatment

1. Explain the structuralbehaviour of plain carbon when heated to 1000oC and carry out heat treatment on plain carbon steel engineering component or tools.
2. Outline and explain the meaning ofhardening in metal work and safety precautions relating to hear treatment processes.
3. Anneal copper,

1. The structural behaviour of plain carbon steel e.g. hardening, tempering, annealing, normalizing, case-hardening.
2. Hardening of metals
3. Heat treatment ofmetals and precautions.
4. The behaviour of steelwhen heated.
5. Hardening andtempering of carbonsteels.
6. Case hardening of mildsteel.
7. Tests for iron and steel.
8. Annealing of metal e.g.a. Copper,

b. Brass etc.

1. Carry out heat treatment of some metals in the workshop e.g. Hardening and tempering of carbon steel tools.
2. Produce simple engineering components based on given specifications.

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brass and aluminium for various purposes.

10.

Forging Processes

1. Explain with sketches, themain features and working principles of the blacksmith forge.
2. Describe with sketches, theforging operations, common forging tools and their functions.
3. Select appropriateforging tools and produce given engineering component.

1. Main features and working principles of blacksmith forge and tools.
2. Equipment for hand forging.
3. How to light a forge.
4. Functions of thecommon forging tools e.g. Anvil, Swage Blockj, Log Vice, Forging Hammers, Hot and Cold Set, Set Hammer, Punches and Drifts, Hardle, Fullers, Top and Bottom Swages Flattes, Tongs, Open mouth, Closed Mount, Hollow etc.
5. Forging operations e.g. upsetting, drawing down, setting down, twisting, forging welding (scarf and splice weld), bending, forming closed ring, forming an eye.
6. Forging tools and production ofengineering components.

Produce simple engineering components based on given specification.

11.

Gas and Arc Welding
1. Describe, set up,

operate and explain the principles and application of gas and metal arc welding

1. Equipment, principles and application of gas and arc welding.
2. Setting and operation of gas or arc welding equipment.
3. Preparation of joints for welding.
4. safety precautions to be

1. Fabricate simple metal components involving both gas and arc welding.
2. Cut a piece of mild steel bar to a givenspecification for a turning between centres operation.

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equipment.

2. Prepare jointsfor welding, weld the components by arc or gas welding method, state and apply the safety precautions involved.
3. Select and sharpen cutting tools, set them up to centre height, differentiate between tools shape, state their function and explain with sketches the effect of wrong setting of cutting tools.
4. Set up, define and calculate the cutting speed and feed with respect to lathe, rate of metal removal, time required for turning operation and carry out turning operations between centres.
5. Compute required taperdimension from giving data using taper rectic angle

observed.

5. welding of componentsby arc and gas weldingmethods.
6. The difference betweenvarious tools shapes and their uses e.g.
   1. Knife tools, round nose roughter,
   2. Fine finishing sidefinishisng, knife tool, form tool, parting off tools, boring tools etc.
7. preparations of tools for turning on lathe machine.
8. Turning operation on a lathe machine
   1. 3 jaw chuck
   2. work piece
   3. cutting tool
9. Setting up of cutting tools for turning and facing operations.
10. Cutting speed and feed with respect to lathe operations.
11. Calculation of cutting speed and feed-line required for a turning operation.
12. Effect of wrong setting with sketches e.g. vibration and chatter, tool rubbing against or digging into the job etc.
13. Chukwork on lathe e.g.
    1. facing, radiusing,chamfering
    2. under cutting,parting off
    3. knurling
    4. step turning

3. Equipment operation should include: choice of correct nozzle of electrode, adjustment for correct gas pressure/flame or voltage etc.
4. Components should be produced to specified tolerance and finish.
5. Calculate or solve a problem involving cutting speed and feed.

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formulae and produce simple components by using compound slide.

6. Set up rough and turned stock in

3-jaw chuk, carry out chuk work and state precautions to be observed when turning between centres.

14. Safety precautions to be observed.
15. Turning operations between centres on lathe machine.
16. Taper ratio calculation with formulae.

Taper ratio = d2 ”“ d1 L

ORTanQ = dz”“di 22

Where
Q = taper angle
di = small end diameter d2 = large end diameter L = length of taper