Session: 7. Forging: a blacksmith's hot punch
Total Time: 2 hours
* To identify and discuss different types of punches and their
* To make a blacksmith's hot punch
* Andrews, page 52.
Materials: 10 - 15 automobile coil springs (6" length and 3/4"
to 5/8" in diameter), and a variety of punching tools.
The punching tools distributed in Step 2 should be assembled in
advance. They should include at least two types of hand-held blacksmith's hot
punch, several cold punches, drifts, mandrels, an awl, nail sets, and center
Step 1. (5 minutes)
Explain the session objectives and
briefly outline the procedures.
Step 2. (10 minutes)
Distribute among the participants a
variety of punching tools used by crafts people and discuss their uses and
* Stimulate a discussion of each tool by asking:
- What are some potential uses for this punch?
- What can be
determined regarding the qualities of the steel from which this tool is
- What are some scrap steels from which this tool could be made?
Which of these punches are used by local crafts people at your work sites?
Step 3. (10 minutes)
Focus the discussion on the hand-held
blacksmith's hot punch and ask participants to identify how it is used.
Some important uses of the punches which should be mentioned
* piercing sheet metal (cold)
* center punching to mark stock
* driving out old rivets, shafts, etc
* hot punching
* drifting (enlarging) holes
Step 4. (10 minutes)
Briefly explain the procedures involved
in making a blacksmith's hot punch.
* Be brief in your explanation and be sure to mention the
importance of making the hot punch long enough to allow holding it while
maintaining a safe distance from the heat of the piece being punched.
* Point out and explain the parallels which exist between the
procedures for making a hot punch and those involved in making a cold chisel.
* Explain that the punch blanks will be annealed and tempered in
the next session, along with their cold chisels.
Step 5. (15 minutes)
Demonstrate the techniques involved in
making a hot punch.
* Before beginning the demonstration, remind participants that
they should observe carefully and note any procedures which appear confusing and
may need to be clarified later.
* During the demonstration, focus your explanation on
identifying transitions from one major step to the next.
Step 6. (10 minutes)
Have the participants review and explain
the procedures and techniques which they observed.
* Before proceeding to the next step in this session, be certain
that all the participants have had the opportunity to clarify the procedures
such that they are ready to begin working at their stations.
Step 7. (50 minutes)
Have participants form their work teams
and practice making a hot punch.
* Circulate among the groups making suggestions, providing
assistance, and pointing out safety precautions and examples of good hammering
Step 8. (10 minutes)
Reconvene the group and ask participants
to discuss and share among themselves any technical difficulties which they
encountered and what they did to overcome