Metalworking

Historical Development of Metalworking

• Oldest evidence of metalworking found in northern Iraq from 8,700 BCE
• Metalworking in the Americas dates back to 4000-5000 BCE in Wisconsin
• Oldest gold artifacts date back to 4450 BCE in Bulgaria
• Metalworking in Mehrgarh, South Asia between 7000 and 3300 BCE
• Metalworking known in ancient civilizations like Egypt, India, Israel, and the Maya
• Precious metals gained value and rules for ownership and trade were established
• Skilled metalworkers created adornments, religious artifacts, and trade instruments
• Techniques like granulation were shared among ancient cultures
• Metal objects became more common and complex, leading to the growth of metalworking skills

Evolution and Categorization of Metalworking Processes

• Metalworking techniques evolved over time
• Skills related to extracting metal ores from the earth developed
• Metalsmiths became important members of society
• Availability of metals and metalsmiths greatly influenced civilizations
• Metalworking is essential for industries, technology, and global trade
• Modern metalworking processes categorized into forming, cutting, and joining processes
• Forming processes shape metals into desired forms
• Cutting processes involve removing material from metals
• Joining processes combine multiple metal parts together
• Machine shops have specialized tools for precise metalworking

Advancements in Materials and Techniques

• Copper and tin were important metals in early metalworking
• Bronze, an alloy of copper and tin, had superior properties for tools and weapons
• Bronze was widely used until the advent of iron
• Metalworking advancements spread globally, with different regions emphasizing different metals
• European colonization brought metalworking for tools and weapons to the Americas

Specific Metalworking Processes

• Bulk forming processes involve using heat or pressure to deform the workpiece
• Sheet (and tube) forming processes apply mechanical force at room temperature
• Cutting involves removing excess material to achieve a specified geometry
• Chip producing processes, such as machining, are commonly used for cutting
• Milling is a complex shaping process that removes material to form the final shape
• Turning is a metal cutting process that produces a cylindrical surface using a single point tool
• Threading processes include cutting threads with a tap or die
• Grinding is an abrasive process to remove material from the workpiece
• Soldering is a joining process that occurs below 450°C (842°F)
• Riveting is an ancient metalwork joining process
• Mechanical fixings, such as screws and bolts, are used for joining metals

Associated Processes and Heat Treatment

• Heat treatment alters metal properties such as strength, ductility, and hardness
• Common heat treatment processes include annealing, precipitation hardening, quenching, and tempering
• Mechanical and thermal treatments can be combined for better properties
• Plating and thermal spraying are common surface-treatment techniques

Metalworking Data Sources