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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 15.4. Bent Pipe

Practise the straightening of a bent pipe with the help of a locksmith's hammer.



- Steel pipe (380 MPa)

diameter: 1 inch

length: 300 mm


Locksmith's hammer, knife

Measuring and testing means

Surface plate, steel rule

Auxiliary means

Vice with prism jaws, box with fine grained sand, 2 wooden plugs, funnel

Required previous knowledge

Manual material working: testing, hammering

Sequence of operations


1. Prepare the working place. Make available the working material.

- Check for completeness.

2. Check the steel pipe on both ends burr, cut two wooden plugs of truncated cone shape and adapt them to the internal diameter of the pipe.

- Stage (1)

- The pipe should be firmly closed when the wooden plug is put in by half its length.

3. Close one end of the pipe firmly with the wooden plug, then fill the pipe completely with sand.

- Stage (2)

4. Strike the pipe shortly on the floor several times.

- The sand filling becomes compact by jolting.

5. Take off some sand and knock the second wood plug firmly into the pipe.

- Stage (3)

6. Clamp the pipe into the vice and straighten it with the help of the locksmith's hammer or by bending.

- Do not slip off!

7. Check evenness by rolling the pipe on the surface plate.

8. Remove the wooden plugs and the sand filling.

Bent Pipe