Work Hardening

Cast copper is relatively soft. Ancient smiths discovered that hammering (cold working) makes it significantly harder — this is work hardening, where deformation compresses the crystal structure.

Remove the casting from the mold. Break off the pouring sprue.
Hammer the tool on an anvil/flat stone. Focus on the working edge (blade, cutting surface).
Hammer in overlapping strokes from center outward. Rotate the piece regularly.
When the copper becomes hard and brittle (resists further hammering, starts cracking at edges), it's fully work-hardened.

Annealing (If Needed)

If you need to reshape a work-hardened piece:

Heat it to cherry red (~600°C) in the kiln
Quench in water
The copper is now soft again — you can continue hammering

This heat-hammer cycle (anneal → cold work → anneal) was the core metallurgical technique for 3,000 years.

Finishing

Grind the working edge on sandstone to create a sharp blade.
Polish with progressively finer abrasive (coarse sand → fine sand → leather).

What You've Made

A functional copper tool — but it's soft compared to stone. Copper axes lose their edge quickly. To make a truly superior metal, you need tin — see Blueprint 06: Extracting Tin and Blueprint 07: Alloying Bronze.

工艺

浏览子分类

木工

金属加工

玻璃加工

石材加工

塑料加工

绳艺

纺织与皮革

陶瓷与粘土

珠宝

纸艺

动物标本剥制

蓝图 (504)

Extracting Tin from Cassiterite — The Missing Ingredient

Casting Copper Tools — Shaping the First Metal

Smelting Copper from Malachite — The Birth of Metallurgy

Building a Clay Kiln — The First Furnace