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		Manual Sawing - Course: Technique for manual working of materials. Instruction examples for practical vocational training (Institut für Berufliche Entwicklung, 31 p.)
			(introduction...)
			Introduction
			Instruction example 4.1. Spacers and pin drifts
			Instruction example 4.2. Stands and supports
			Instruction example 4.5. Container
			Instruction example 4.4. Vee-shaped attachment
			Instruction example 4.5. Steel square
			Instruction example 4.6. Angle-steel frame table
			Instruction example 4.7. Wall-shelf bracket

Instruction example 4.7. Wall-shelf bracket

To practise mitre cuts with increased level of difficulties and bevel cuts and cutouts on angles.

Material

- Unequal-leg angles of any steel 20 x 30 x 4 thick, approx. 1000 mm long.
- Sheet steel
70 x 70 x 2.5 thick.
- 4 button-head rivets
4 mm diameter
(of copper or aluminium).

Figure

Hand tools

Steel scriber, mark-out punch, engineers’ hammer, hand hacksaw (saw blade with normal tooth pitch), 4.1 mm dia. and 5.5 mm dia. drills, 75° countersink, smooth-cut file 250 mm (flat).

Measuring and testing tools

Steel measuring tool, try square.

Accessories

Vice, surface plate, levelling plate, rivet set for 4 mm dia. rivets, rivet header for 4 mm dia. rivets, pin vice.

Required previous knowledge

Reading of drawings, measuring and testing, scribing and punch-marking.

Sequence of operations

Comments

1. Arrange the working place, prepare the working materials.

- Check for completeness.

2. Scribe the angles and saw to initial length. Saw out the pivot at one end face 6 x 10, remove burrs with the file.

- Determine length by width of shelf!
- Note: left-hand and right-hand wall-shelf bracket.

3. Scribe centre and 90° mitre angle (inside), saw out the angle, remove burrs.

- Stage (1)
Clamp angle so that sawing cut will be vertical!

4. Bend the angle in the vice by means of the engineers’ hammer, bend the pivot (upward).

- Stage (2)
Check for right-angularity by means of try square.

5. Saw out the steel sheet to specified size, remove burrs.

- Stage (3)

6. Inspection of cuts.

Completion
- Scribe holes on steel sheet, prick-punch and drill with 4.1 mm dia. drill.

- Drill under supervision of the instructor with steel sheet clamped in pin vice. Speed: approx. 1400 r.p.m.

- Insert the drilled sheet inside the bent angles and prick-punch the angles through the holes of the sheet, drill with 4.1 mm dia. drill.

- Use sheet as stencil!

- Scribe and prick-punch the 5.5 mm dia. holes, drill all scribed holes.

- Pay attention to specified sizes!

- Countersink 4.1 mm dia. holes from the outside of the angles with 75° countersink.

- Speed: approx. 350 r.p.m.
Countersink diameter: 7.0 mm

- Clamp angle and sheet together in pin vice, then rivet together

- Stage (4)

Wall-shelf bracket

Sequence of operations	Comments
1. Arrange the working place, prepare the working materials.	- Check for completeness.
2. Scribe the angles and saw to initial length. Saw out the pivot at one end face 6 x 10, remove burrs with the file.	- Determine length by width of shelf! - Note: left-hand and right-hand wall-shelf bracket.
3. Scribe centre and 90° mitre angle (inside), saw out the angle, remove burrs.	- Stage (1) Clamp angle so that sawing cut will be vertical!
4. Bend the angle in the vice by means of the engineers’ hammer, bend the pivot (upward).	- Stage (2) Check for right-angularity by means of try square.
5. Saw out the steel sheet to specified size, remove burrs.	- Stage (3)
6. Inspection of cuts.

Completion - Scribe holes on steel sheet, prick-punch and drill with 4.1 mm dia. drill.	- Drill under supervision of the instructor with steel sheet clamped in pin vice. Speed: approx. 1400 r.p.m.
- Insert the drilled sheet inside the bent angles and prick-punch the angles through the holes of the sheet, drill with 4.1 mm dia. drill.	- Use sheet as stencil!
- Scribe and prick-punch the 5.5 mm dia. holes, drill all scribed holes.	- Pay attention to specified sizes!
- Countersink 4.1 mm dia. holes from the outside of the angles with 75° countersink.	- Speed: approx. 350 r.p.m. Countersink diameter: 7.0 mm
- Clamp angle and sheet together in pin vice, then rivet together	- Stage (4)