The impact of the hitting hammer face is transmitted through the workpiece to the strong, inflexible support which is repelling the blow.
The material gets compressed - it cannot yield in the direction of the blow.
It yields to two or more sides, depending on the shape of the hitting hammer head and on the shape of the hammering support, with such shapes getting impressed into the surface of the workpiece.
Figure 14 Effect of hammer pane and
hammer face
Notes
- Ductile materials can be hammered only - brittle materials cannot be formed by hammering!- The more hammer blows, the faster hardening and the harder the material!
- In case of extensive forming operations the hardness is to be reduced by annealing and cooling down!
- Sheet steel is to be cooled down gradually in the air after annealing - sheet copper is to be quenched in cold water immediately after annealing!
To ensure maximum hitting accuracy, the blow of the hammer should be directed from the wrist joint.
More powerful blows for heavy forming work should be directed from the shoulder joint.
What is the working principle of hammering?
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What property must materials have that shall be hammered?
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What is the effect of many hammer blows hitting one point of the workpiece?
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How can that effect be reduced or eliminated?
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