Cover Image
close this bookStraightening - Course: Technique of Working Sheet Metals, Pipes and Sections. Instruction Examples for Practical Vocational Training
View the document(introduction...)
View the documentPreliminary Remarks
View the documentInstruction Example 15.1. Bendings and Bucklings
View the documentInstruction Example 15.2. Twistings
View the documentInstruction Example 15.3. Bent Angle Section
View the documentInstruction Example 15.4. Bent Pipe
View the documentInstruction Example 15.5. Dented and Corrugated Metal Sheets

Instruction Example 15.1. Bendings and Bucklings

Practise the straightening of buckled metal sheets and flat material as well as bent square sections by means of the hand screw press, the locksmith's hammer and the welding torch.



- Steel sheet (300 MPa) (1)

thickness: 2 mm

width: 80 mm

length: 250 mm

- Flat material (380 MPa) (2)

thickness: 8 mm

width: 30 mm

length: 250 mm

- Square section (380 MPa) (3)

thickness: 15 mm

length: 250 mm

Tools and devices

Locksmith's hammer, hand screw press, welding torch with accessories

Measuring and testing means

Surface plate, workshop ruler, steel rule

Auxiliary means

Straightening plate or anvil, vice

Required previous knowledge

Manual working of materials: testing, hammering

Sequence of operations


1. Prepare the working place; make available the working material.

- Check for completeness.

2. Put the buckled steel sheet (1) under the flat punch of the hand screw press, then let the screw move down by a powerful swing.

- Protect hands and head when the scew gets down.

3. Put the straightened steel sheet on the surface plate and check its eveness - if necessary straighten it again.

- When touching the comers of the metal sheet with the finger, the sheet metal must not wobble.

4. Clamp the buckled flat material (2) vertically in the vice and straighten the projecting end opposite to the direction of the buckling; by means of hammer blows with the locksmith's hammer then flatten it on the straightening plate by even hammer blows.

- The buckling must be exactly above the jaws of the vice.

Do not strike too many hammer blows - embrittlement

5. Check the straightened flat material for evenness by means of the workshop ruler on the surface plate.

6. Clamp the bent square section (3) laterally in the vice; heat up the bent end by the welding torch and straighten it with the help of the locksmith's hammer.

- Attention! Danger of fire!

- The welding torch is allowed to be operated only after instruction by the instructor.

7. Check evenness of the straightened square section by means of the workshop ruler.

Bendings and Bucklings