Aim: - To mark punch and drill holes on a metal sheet.
Tool required: - Drilling machine, drill chuck, machine vice, twist drill bits, flat file, by
square, hacksaw, centre punch and hammer.
Material required: - Mild steel flat.
Instrument required: - Steel rule, scriber, and vernier caliper.
1. A flat piece of required dimension is to be cut using hacksaw.
2. Both edges are filed and checked for square ness using try square.
3. Chalk solution is applied on the surface of metal and left to dry.
4. Dried metal piece is marked as per dimension given in the drawing using steel rule
5. Centre of the hole is marked using centre punch and hammer.
6. Job is clamped in the vice of drilling machine keeping the marked surface upward and
enlarges the centre of the hole using centre drill in the machine.
7. The centre drill is taken out and the drills of required sizes are fitted in the drill chuck
of the machine and drill the job.
Feed to be applied slowly in the beginning
Heavy feed may damage the drill bits. Don’t use too much pressure on the feed handle.
Coolant to be used.
Hand gloves, apron and shoes must be used while working.
Work piece should be firmly tightened in the vice of the machine.