Casting Equipment, Sand, Die and Shell Casting for SS 3

Class: SS 3
Term: First Term
Week: 3
Age: 16 years
Duration: 45 minutes
Subject: Metal Work
Topic: Material and equipment for casting.
Subject Matter: Type of casting equipment: sand casting, die casting, and shell casting; skekches of typical casting mould
Previous Lesson: Sand Casting, Die Casting and Shell Moulding Methods

Specific Objectives

By the end of the lesson, pupils/students should be able to:

Cognitive Domain

• Identify different types of casting equipment.
• Explain the process of sand casting.
• Describe the process of die casting.
• Outline the process of shell casting.

Affective Domain

• Appreciate the importance of safety measures in casting operations.
• Value the precision and efficiency of different casting methods.

Psychomotor Domain

• Sketch typical casting moulds for various processes.
• Demonstrate the basic setup of casting equipment for practical activities.

Social Domain

• Collaborate effectively during practical activities involving casting equipment.

Reference Materials

The following resources were used in planning this lesson:

• 2025 Revised 9 Years Basic Education Curriculum
• Relevant State Unified Scheme of Work
• Metal Work for Senior Secondary Schools Textbook
• The HeadTeacher Scheme of work

Instructional Materials

The teacher will teach this lesson with the aid of:

• Charts showing different casting equipment.
• Diagrams illustrating sand, die, and shell casting processes.
• Samples of casting moulds (if available).
• Hand tools for mould preparation (e.g., trowel, rammer).
• Sand, pattern, and moulding box for demonstration.

Rationale for the Lesson

This lesson provides students with foundational knowledge of various metal casting techniques and the equipment involved. Understanding these processes is essential for comprehending how metal components are manufactured and for developing practical skills in metal fabrication. It also highlights the importance of precision and safety in industrial processes.

Prerequisite/Previous Knowledge

Students should have basic knowledge of metals, their properties, and general workshop safety rules.

Lesson Content/Board Summary

Material and equipment for casting.

Types of Casting Equipment and Processes

Casting is a manufacturing process in which a liquid material is usually poured into a mould, which contains a hollow cavity of the desired shape, and then allowed to solidify. The solidified part is also known as a casting, which is ejected or broken out of the mould to complete the process.

The main types of casting equipment and processes include:

1. Sand Casting:

• Process: This is the most common and versatile casting process. It involves creating a mould from sand (typically silica sand mixed with a binder) around a pattern (a replica of the desired part). Molten metal is poured into this sand mould. Once solidified, the sand mould is broken away to retrieve the casting.
• Equipment: Pattern, moulding box (flask), moulding sand, rammer, trowel, riddle, sprue pin, risers, gates, pouring ladle, furnace.

• Process: This method involves forcing molten metal under high pressure into a reusable metal mould cavity (die). The die is typically made from hardened tool steel. It is suitable for producing large quantities of small to medium-sized castings with excellent surface finish and dimensional accuracy.
• Equipment: Die casting machine (hot-chamber or cold-chamber), dies (moulds), furnace.

• Process: Shell casting uses a thin, hard shell of sand and resin as the mould. A metal pattern is heated, coated with a mixture of sand and thermosetting resin, which cures to form a thin, strong shell. This shell is then separated from the pattern, assembled, and supported with backing material before molten metal is poured into it.
• Equipment: Metal pattern, shell moulding machine, sand-resin mixture, furnace, pouring ladle.

Sketches of Typical Casting Moulds

Casting moulds are designed to create a cavity that matches the desired shape of the final product. While specific designs vary greatly, typical features include:

1. Sand Casting Mould:

• Components: Consists of two halves (cope and drag) of a moulding box, separated by a parting line. Inside, there is a cavity formed by the pattern, a sprue (main channel for molten metal), runners (channels to the cavity), gates (entry points into the cavity), and risers (reservoirs to compensate for shrinkage).
• Appearance: A block of compacted sand with internal channels and a central cavity.

• Components: Two precision-machined steel halves (cover die and ejector die) that fit together tightly. It includes the mould cavity, a sprue or shot hole, cooling channels, and ejector pins to remove the solidified casting.
• Appearance: Heavy, metallic blocks with intricate internal cavities and channels.

• Components: A thin, rigid shell made from sand and resin, usually in two halves. It has a smooth internal surface that replicates the pattern, with provisions for sprue, runners, and risers.
• Appearance: A relatively thin, hard, and smooth shell that looks like a hollowed-out version of the finished part.

Teaching Methods/Instructional Techniques

Discussion, Demonstration, Guided Practice, Question and Answer, Explanation, Observation, Practical Activity.

Instructional Procedures

Step 1: Introduction

Time: 5 minutes

Teaching Skill: Recalling/Engaging

Teacher’s Activity: The teacher greets the students and reviews the previous lesson on basic metal properties. The teacher then introduces the new topic, “Material and equipment for casting,” by asking students if they know how complex metal shapes are made.

Pupils’ Activity: Students respond to questions and listen attentively to the introduction of the new topic.

Learning Point: Introduction to casting

Step 2: Identifying Casting Equipment

Time: 8 minutes

Teaching Skill: Explanation/Identification

Teacher’s Activity: The teacher lists and displays charts or diagrams of various casting equipment, such as patterns, moulding boxes, furnaces, and ladles. The teacher explains the function of each piece of equipment.

Pupils’ Activity: Students observe the charts/diagrams, listen to explanations, and identify the equipment.

Learning Point: Casting equipment identification

Step 3: Explaining Sand Casting

Time: 7 minutes

Teaching Skill: Demonstration/Explanation

Teacher’s Activity: The teacher explains the sand casting process step-by-step, using diagrams or a simplified practical demonstration with a pattern and moulding sand to show mould creation.

Pupils’ Activity: Students observe the demonstration, ask questions, and take mental notes on the sand casting process.

Learning Point: Sand casting process

Step 4: Explaining Die Casting

Time: 6 minutes

Teaching Skill: Explanation/Visualisation

Teacher’s Activity: The teacher describes the die casting process, emphasising the use of reusable metal dies and high pressure. The teacher uses diagrams to illustrate the hot-chamber and cold-chamber methods.

Pupils’ Activity: Students listen to the explanation and visualise the process through diagrams.

Learning Point: Die casting process

Step 5: Explaining Shell Casting

Time: 6 minutes

Teaching Skill: Explanation/Comparison

Teacher’s Activity: The teacher explains the shell casting process, highlighting the use of a thin sand-resin shell mould. The teacher compares its advantages and disadvantages with sand casting.

Pupils’ Activity: Students listen, compare the processes, and ask clarifying questions.

Learning Point: Shell casting process

Step 6: Sketching Typical Casting Moulds

Time: 5 minutes

Teaching Skill: Drawing/Guidance

Teacher’s Activity: The teacher guides students through sketching typical features of sand, die, and shell casting moulds on the board, pointing out key components like sprue, runners, and cavity.

Pupils’ Activity: Students sketch the moulds in their notebooks, following the teacher’s guidance.

Learning Point: Casting mould sketches

Step 7: Evaluation/Review

Time: 5 minutes

Teaching Skill: Questioning/Assessment

Teacher’s Activity: The teacher evaluates the learning by asking the following questions:

1. List three types of casting equipment.
2. Briefly explain the sand casting process.
3. What is the main difference between sand casting and die casting?
4. Describe one advantage of shell casting.

Pupils’ Activity: Pupils answer orally and in writing.

Learning Point: Understanding casting methods

Step 8: Note-Taking

Time: 4 minutes

Teaching Skill: Guided Writing

Teacher’s Activity: The teacher guides pupils/students to copy the essential Board Summary notes on casting equipment and processes into their notebooks.

Pupils’ Activity: Pupils/students copy the notes carefully into their notebooks.

Learning Point: Recording lesson notes

Step 9: Conclusion

Time: 2 minutes

Teaching Skill: Summarising

Teacher’s Activity: The teacher summarises the key points of the lesson, reiterating the different casting methods and their unique characteristics. The teacher reminds students about the importance of safety in metal work.

Pupils’ Activity: Students listen to the summary and prepare for the next lesson.

Learning Point: Lesson consolidation

Continuous Assessment/Further Study

Type: Homework/Practice Exercise

Instruction: Answer the following questions in your notebook.

1. Draw and label a simple diagram of a sand casting mould, showing the cope, drag, cavity, sprue, and riser.
2. Research and write a short paragraph on the safety precautions necessary when working with molten metals in a casting workshop.
3. Identify two products commonly made using die casting and two using sand casting.

Lesson Keywords

• Casting – A manufacturing process where liquid material is poured into a mould and allowed to solidify.
• Sand Casting – A casting process using sand as the mould material.
• Die Casting – A casting process where molten metal is forced into a metal die under high pressure.
• Shell Casting – A casting process using a thin, hard shell of sand and resin as the mould.
• Mould – A hollow form used to give shape to molten material.
• Pattern – A replica of the object to be cast, used to create the mould cavity.

Differentiation

For weaker learners, provide simplified diagrams and focus on identifying the main casting types and their basic equipment. For faster learners, encourage research into advanced casting techniques or the metallurgy of specific casting alloys, and challenge them to identify industrial applications for each casting method.

Suggested Lesson Videos

Search on YouTube for:
“Sand casting process explained”
“Die casting manufacturing”
“Shell moulding process animation”

Teacher Guide for Using This Lesson Plan

Before the lesson, ensure all charts and diagrams of casting equipment and processes are ready. If possible, gather simple items that can represent patterns, moulding sand, and a moulding box for a hands-on demonstration of sand mould creation. Emphasise safety protocols when discussing or demonstrating any practical aspects of casting. Guide students through the identification of equipment and the step-by-step explanation of each casting process. Encourage questions and active participation. Allow sufficient time for students to sketch the mould types. The Board Summary should be copied by students at Step 8, ensuring they have accurate notes for future reference. Check for understanding throughout the lesson, especially during the evaluation phase, and provide support for any misconceptions.