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close this bookAnnealing, Hardening, Tempering - Course: Working Techniques of Heat Treatment of Steel. Instruction Examples for Practical Vocational Training
View the document(introduction...)
View the documentIntroductory Remarks
View the documentInstruction Example 16.1.: Spiral Spring
View the documentInstruction Example 16.2.: Marking and Riveting Tools
View the documentInstruction Example 16 3.: Flat Chisel and Cape Chisel
View the documentInstruction example 16.4.: Assembly Tools
View the documentInstruction Example 16.5.: Locksmith's Hammer
View the documentInstruction Example 16.6.: Testing Means

Instruction example 16.4.: Assembly Tools

Practise the interrupted hardening with subsequent tempering from outside.


Prefabricated hexagon socket wrench, box wrench, screw driver made of tool steel with a carbon content between 1 and 1.1%


Tools and Devices

Furnace, quenching tank (two pieces), abrasive cloth, file

Auxiliary accessories

Powerful quenching medium (water), mild quenching medium (lubricating oil heated to 150°C), scouring cloth (fat-free)

Previous knowledge required

Manual working of materials

Sequence of operations


1. Prepare workplace
Make working material available

Check for completeness

2. Fire the furnace and bring to nominal temperature

In case of an existing temperature controller, adjust hardening temperature

3. Heat quenching tank with lubricating oil up to approx. 150°C

4. Place tools with the side to be hardened into the furnace and heat up to hardening temperature

Phase 1
Annealing colour: dark cherry-red 770°C

5. After having reached the hardening temperature, keep for approx. 1 minute

6. Dip tools into the quenching tank filled with water, for a short time

Until hissing fades away!

7. Dip tools into the quenching tank with heated oil

Phase 2
Until temperature balance

8. Let tools cool down in air

Phase 3

9. Clean tools, carry out hardness test

File test

10. Grind tools at hardened side blank

Abrasive cloth

11. Heat tools in the furnace once again

Phase 4
Temper colour; purple 270°C

12. After having reached the tempering temperature, cool down tools

Phase 5

13. Clean tools and again carry out hardness test

File test, functional test

Assembly Tools