Manual Metal-Arc Welding - (Overhead) - Low Carbon Steel — SEG Awards Vocationally-Related Qualification Design and Technology Revision

    This unit covers manual metal-arc welding in the overhead position on low carbon steel. Learners must understand safety, equipment, electrode types, and we

    Topic Synopsis

    This unit covers manual metal-arc welding in the overhead position on low carbon steel. Learners must understand safety, equipment, electrode types, and welding parameters to produce sound welds.

    Key Concepts & Core Principles

    Exam Tips & Revision Strategies

    Common Misconceptions & Mistakes to Avoid

    Examiner Marking Points

    Manual Metal-Arc Welding - (Overhead) - Low Carbon Steel

    SEG AWARDS
    vocational

    This unit covers manual metal-arc welding in the overhead position on low carbon steel. Learners must understand safety, equipment, electrode types, and welding parameters to produce sound welds.

    1
    Learning Outcomes
    3
    Assessment Guidance
    3
    Key Skills
    1
    Key Terms
    5
    Assessment Criteria

    Assessment criteria

    SEG Awards Level 3 Diploma in Welding Techniques and Skills

    Topic Overview

    The SEG Awards Level 3 Diploma in Welding Techniques and Skills is a vocationally-related qualification designed for students who want to develop advanced practical welding skills and theoretical knowledge. This diploma covers a range of welding processes including Manual Metal Arc (MMA), Metal Inert Gas (MIG), Tungsten Inert Gas (TIG), and Flux-Cored Arc Welding (FCAW). Students learn to interpret engineering drawings, select appropriate welding parameters, and produce high-quality welds in various positions. The qualification also emphasises health and safety, quality control, and inspection techniques, preparing students for careers in industries such as construction, manufacturing, and automotive engineering.

    This diploma is part of the wider Design and Technology curriculum, bridging the gap between theoretical design principles and practical fabrication. It equips students with the skills to work with ferrous and non-ferrous metals, understand metallurgy, and apply welding codes and standards. Mastery of these techniques is essential for producing safe, durable structures and components. The qualification also develops problem-solving abilities, attention to detail, and the capacity to work independently or as part of a team—skills highly valued by employers and further education providers.

    By completing this diploma, students gain a recognised Level 3 qualification that can lead to advanced apprenticeships, higher education in engineering, or direct employment as a skilled welder. The course integrates practical assessments with written exams, ensuring a comprehensive understanding of welding theory and practice. It is ideal for those who enjoy hands-on work and want to build a career in a skilled trade that offers global opportunities.

    Key Concepts

    Core ideas you must understand for this topic

    • →Welding processes: Understand the principles, advantages, and limitations of MMA, MIG/MAG, TIG, and FCAW. Know when to use each process based on material type, thickness, and joint configuration.
    • →Welding positions: Master flat, horizontal, vertical, and overhead welding. Each position requires specific techniques to control the weld pool and achieve penetration without defects.
    • →Metallurgy: Learn how heat affects the microstructure of metals, including phase transformations in steel, and how to control cooling rates to minimise distortion and cracking.
    • →Weld defects and inspection: Identify common defects like porosity, slag inclusion, undercut, and lack of fusion. Understand non-destructive testing (NDT) methods such as visual inspection, dye penetrant, and ultrasonic testing.
    • →Health and safety: Comply with COSHH regulations, use personal protective equipment (PPE), ensure adequate ventilation, and follow safe working practices to prevent burns, electric shock, and fume inhalation.

    Learning Objectives

    What you need to know and understand

    • 1.1. Identify the roles of various organisations involved with safety in the workplace, to include:• Health and Safety Executive (HSE)• Environmental Health• Local Authorities1.2. Identify the roles of various individuals involved with health and safety in the workplace, to include:• Company safety officers• Company safety representatives• Environmental health officers• HSE inspectors1.3. Identify the purpose for and typical contents of an organisations’ Health and Safety Policy1.4. Describe the purpose of a risk assessment, to include:• who should carry out risk assessments• when to carry out a risk assessment• identification of the 5 steps of risk assessment1.5. Identify the precautions to be taken when working in high risk areas, to include:• risk assessments• permits to work• high/low temperature working conditions• lock off systems• isolation of equipment1.6. Describe the control and safe removal of welding fumes and gases created during the welding process, to include:• natural extraction• local extraction• PPE and specialist breathing equipment1.7. Identify the different power sources used in MMA welding, to include:• transformer• generator• rectifier• invertor1.8. Describe features of the power sources as listed in 2.1, to include:• type of current produced (AC/DC) • maintenance requirements• portability• suitable applications 1.9. Identify the advantages and limitations of using both alternating current (AC) and direct current (DC)1.10. Describe how the electrical features listed affect the MMA welding process:• change of polarity when using direct current (DC)• current control (tapped, moving core and moving coil)• duty cycle of the power source • drooping characteristic feature1.11. Describe the importance of correct storage conditions for electrodes, to include:• location• ventilation• contamination• labelling1.12. Identify the use of different types of electrodes, to include:• cellulosic• rutile• basic (low hydrogen)1.13. Describe the reasons why basic (low hydrogen) electrodes require special conditions when being stored prior to use1.14. Describe the effects of using damaged or damp electrodes1.15. Identify the functions of:• flux coating on the electrode• slag covering on the weld deposit1.16. Identify and select the welding parameters to be used when welding low carbon steel in the overhead welding position (PE), to include:• welding current• OCV (open circuit voltage)• electrode slope and tilt angles• arc length• speed of travel• electrode polarity1.17. Identify which parameters may need a different selection when welding stainless steel or aluminium in the overhead position (PE)1.18. Identify suitable welding preparations for the type of joint and material thickness being welded, to include:• included angle• angle of bevel• root face dimension• root gap dimension1.19. Describe the advantages and limitations of the methods listed that are used to produce suitable welding preparations on materials, to include:• thermal methods• mechanical (chip forming)• shearing• bevelling machines• abrasive methods1.20. Identify the main types of distortion found in completed welded joints, to include:• longitudinal• transverse• angular1.21. Describe the significance of residual stress found in welded joint1.22. Identify the main causes of distortion in welded joints1.23. Identify methods used to control distortion in welded joints1.24. Identify appropriate safety checks on the welding equipment prior to use1.25. Select suitable welding parameters to enable the listed joints to be welded by the MMA welding process on low carbon steel or stainless steel.• tee fillet (PE)• butt weld(PE)• open outside corner (PE)• lap joint (PE)1.26. Carry out destructive tests on the completed welds and document the results. Tests to include:• face bend• root bend• fracture test1.27. Identify defects and imperfections that may be found in welds completed in the overhead position (PE) by the MMA welding process1.28. Identify the use of aids whe

    Assessment Criteria

    Key criteria assessors look for in your portfolio

    • Identifies roles of HSE and other safety organisations.
    • Describes risk assessment steps and precautions for high-risk areas.
    • Selects correct welding parameters for overhead position.
    • Produces welds with minimal defects and acceptable appearance.
    • Performs destructive tests and interprets results.

    Assessment Guidance

    Guidance for achieving higher grades

    • 💡Practise overhead welding on scrap pieces to master technique.
    • 💡Memorise the five steps of risk assessment.
    • 💡Understand how polarity affects weld penetration.
    • 💡Always refer to welding standards (e.g., BS EN ISO) when describing procedures. Examiners look for evidence that you can apply industry codes to real situations, not just recall facts.
    • 💡In practical assessments, demonstrate your setup process: check equipment, select parameters, and prepare the joint. Examiners award marks for methodical working and safety awareness, not just the final weld.
    • 💡When answering theory questions, use correct terminology (e.g., 'arc length', 'travel speed', 'included angle') and explain the 'why' behind techniques. For example, explain why a short arc length reduces spatter in MMA welding.

    Common Mistakes

    Common errors to avoid in your coursework

    • Using incorrect electrode angle or travel speed for overhead welding.
    • Ignoring fume extraction or PPE requirements.
    • Failing to control distortion due to improper sequencing.
    • Misconception: 'MIG welding is always easier than TIG welding.' Correction: While MIG is often faster and more forgiving on dirty materials, TIG offers greater control and is essential for thin materials or aesthetic welds. Each process has its own challenges.
    • Misconception: 'A bigger weld is always stronger.' Correction: Oversized welds can introduce excessive heat input, leading to distortion and residual stress. The correct weld size is determined by the joint design and load requirements, not by making it as large as possible.
    • Misconception: 'You don't need to clean the metal before welding.' Correction: Contaminants like rust, oil, paint, and moisture cause porosity and weak welds. Proper cleaning with a wire brush, grinder, or solvent is critical for weld quality.

    Frequently Asked Questions

    Common questions students ask about this topic

    Before You Start

    Prior knowledge that will help with this topic

    • •Understanding of basic engineering drawings and symbols, including weld symbols to BS EN ISO 2553.
    • •Knowledge of material properties for common metals like mild steel, stainless steel, and aluminium.
    • •Basic workshop safety practices and experience with hand tools and measuring instruments.

    Key Terminology

    Essential terms to know

    • 1.1. Identify the roles of various organisations involved with safety in the workplace, to include:• Health and Safety Executive (HSE)• Environmental Health• Local Authorities1.2. Identify the roles of various individuals involved with health and safety in the workplace, to include:• Company safety officers• Company safety representatives• Environmental health officers• HSE inspectors1.3. Identify the purpose for and typical contents of an organisations’ Health and Safety Policy1.4. Describe the purpose of a risk assessment, to include:• who should carry out risk assessments• when to carry out a risk assessment• identification of the 5 steps of risk assessment1.5. Identify the precautions to be taken when working in high risk areas, to include:• risk assessments• permits to work• high/low temperature working conditions• lock off systems• isolation of equipment1.6. Describe the control and safe removal of welding fumes and gases created during the welding process, to include:• natural extraction• local extraction• PPE and specialist breathing equipment1.7. Identify the different power sources used in MMA welding, to include:• transformer• generator• rectifier• invertor1.8. Describe features of the power sources as listed in 2.1, to include:• type of current produced (AC/DC) • maintenance requirements• portability• suitable applications 1.9. Identify the advantages and limitations of using both alternating current (AC) and direct current (DC)1.10. Describe how the electrical features listed affect the MMA welding process:• change of polarity when using direct current (DC)• current control (tapped, moving core and moving coil)• duty cycle of the power source • drooping characteristic feature1.11. Describe the importance of correct storage conditions for electrodes, to include:• location• ventilation• contamination• labelling1.12. Identify the use of different types of electrodes, to include:• cellulosic• rutile• basic (low hydrogen)1.13. Describe the reasons why basic (low hydrogen) electrodes require special conditions when being stored prior to use1.14. Describe the effects of using damaged or damp electrodes1.15. Identify the functions of:• flux coating on the electrode• slag covering on the weld deposit1.16. Identify and select the welding parameters to be used when welding low carbon steel in the overhead welding position (PE), to include:• welding current• OCV (open circuit voltage)• electrode slope and tilt angles• arc length• speed of travel• electrode polarity1.17. Identify which parameters may need a different selection when welding stainless steel or aluminium in the overhead position (PE)1.18. Identify suitable welding preparations for the type of joint and material thickness being welded, to include:• included angle• angle of bevel• root face dimension• root gap dimension1.19. Describe the advantages and limitations of the methods listed that are used to produce suitable welding preparations on materials, to include:• thermal methods• mechanical (chip forming)• shearing• bevelling machines• abrasive methods1.20. Identify the main types of distortion found in completed welded joints, to include:• longitudinal• transverse• angular1.21. Describe the significance of residual stress found in welded joint1.22. Identify the main causes of distortion in welded joints1.23. Identify methods used to control distortion in welded joints1.24. Identify appropriate safety checks on the welding equipment prior to use1.25. Select suitable welding parameters to enable the listed joints to be welded by the MMA welding process on low carbon steel or stainless steel.• tee fillet (PE)• butt weld(PE)• open outside corner (PE)• lap joint (PE)1.26. Carry out destructive tests on the completed welds and document the results. Tests to include:• face bend• root bend• fracture test1.27. Identify defects and imperfections that may be found in welds completed in the overhead position (PE) by the MMA welding process1.28. Identify the use of aids whe

    Ready to learn?

    AI-powered learning tailored to this unit

    Related Topics in SEG AWARDS vocational Design and Technology

    12. Advanced Fabrication Processes – Plate (3 mm and Above in Thickness)

    View Topic

    6. Fabrication Processes – Sheet Metal

    View Topic

    Advanced Fabrication Processes – Sheet Metal (below 3 mm in Thickness)

    View Topic

    Engineering Drawing

    View Topic