All qualifications and part qualifications registered on the National Qualifications Framework are public property. Thus the only payment that can be made for them is for service and reproduction. It is illegal to sell this material for profit. If the material is reproduced or quoted, the South African Qualifications Authority (SAQA) should be acknowledged as the source. |
SOUTH AFRICAN QUALIFICATIONS AUTHORITY |
REGISTERED UNIT STANDARD THAT HAS PASSED THE END DATE: |
Demonstrate understanding of the mechanical properties of bolts set screws and welds and their application in the design of connections for structural steelwork assemblies |
SAQA US ID | UNIT STANDARD TITLE | |||
114197 | Demonstrate understanding of the mechanical properties of bolts set screws and welds and their application in the design of connections for structural steelwork assemblies | |||
ORIGINATOR | ||||
SGB Civil Engineering Construction | ||||
PRIMARY OR DELEGATED QUALITY ASSURANCE FUNCTIONARY | ||||
- | ||||
FIELD | SUBFIELD | |||
Field 12 - Physical Planning and Construction | Civil Engineering Construction | |||
ABET BAND | UNIT STANDARD TYPE | PRE-2009 NQF LEVEL | NQF LEVEL | CREDITS |
Undefined | Regular | Level 5 | Level TBA: Pre-2009 was L5 | 8 |
REGISTRATION STATUS | REGISTRATION START DATE | REGISTRATION END DATE | SAQA DECISION NUMBER | |
Passed the End Date - Status was "Reregistered" |
2018-07-01 | 2023-06-30 | SAQA 06120/18 | |
LAST DATE FOR ENROLMENT | LAST DATE FOR ACHIEVEMENT | |||
2026-06-30 | 2029-06-30 |
In all of the tables in this document, both the pre-2009 NQF Level and the NQF Level is shown. In the text (purpose statements, qualification rules, etc), any references to NQF Levels are to the pre-2009 levels unless specifically stated otherwise. |
This unit standard does not replace any other unit standard and is not replaced by any other unit standard. |
PURPOSE OF THE UNIT STANDARD |
A person credited with this unit standard will be able to:
Describe and illustrate various types of bolts, set screws and pre-tensioned bolts and their mechanical properties in structural steelwork applications. Describe failure modes and calculate resistances of bearing type bolts and set screws, bolts and set screws in shear, bolts and set screws in direct tension. Describe the behaviour of slip-resistant joints and calculate resistances of joints where pre-tensioned bolts are used. Explain and discuss welding principles and weld processes and illustrate welded joints and weld types. Explain and illustrate weld defects and weld strengths. The contribution to The National Skills Development Strategy is the key developmental interface between learners and new competencies to be achieved. Learners who master the competence described in this unit standard will be able to use their knowledge of bolt and weld properties and their application in the design of connections for bolted and welded components. |
LEARNING ASSUMED TO BE IN PLACE AND RECOGNITION OF PRIOR LEARNING |
The following knowledge, skills, attitude and/or equivalent:
|
UNIT STANDARD RANGE |
Range of classes of connectors include but are not limited to:
Range of shear resistances include but are not limited to: Range of surface conditions include but are not limited to: Range of welding processes include but are not limited to: Range of effects of heat input include but are not limited to: Range of joint types include but are not limited to: Range of weld types include but are not limited to: Range of groove weld resistances include but are not limited to: Range of internal force systems occurring on weld joints includes but is not limited to: Direct forces, shear forces, transverse shear forces and moments |
Specific Outcomes and Assessment Criteria: |
SPECIFIC OUTCOME 1 |
Describe and illustrate various types of bolts, set screws and pre-tensioned bolts. |
OUTCOME NOTES |
Describe and illustrate various types of bolts, set screws and pre-tensioned bolts and their mechanical properties in structural steelwork applications. |
ASSESSMENT CRITERIA |
ASSESSMENT CRITERION 1 |
1. The application of bolts and set screws in bearing, shear and direct tension is described and illustrated. |
ASSESSMENT CRITERION 2 |
2. The application of pre-tensioned bolts is described and illustrated. |
ASSESSMENT CRITERION 3 |
3. Classes of bolts, set screws and pre-tensioned bolts are listed in accordance with SABS 1700. |
ASSESSMENT CRITERION 4 |
4. Minimum Tensile Strengths, Minimum Yield Stresses and Proof Load stresses of bolts, set screws and pre-tensioned bolts are listed in accordance with SABS 1700. |
ASSESSMENT CRITERION 5 |
5. Minimum % Elongation at Fracture of bolts, set screws and pre-tensioned bolts are listed in accordance with SABS 1700 and its importance in relation to ductility is explained. |
SPECIFIC OUTCOME 2 |
Describe failure modes and calculate resistances of bearing type bolts and set screws. |
ASSESSMENT CRITERIA |
ASSESSMENT CRITERION 1 |
1. Failure modes of plates subject to bolts and set screws in bearing are described. |
ASSESSMENT CRITERION 2 |
2. Equations for calculating bearing resistances are stated and explained for different conditions in accordance with SABS 0162-1: 1993. |
ASSESSMENT CRITERION 3 |
3. Plate resistances are calculated for bearing type connections in accordance with SABS 0162-1: 1993. |
SPECIFIC OUTCOME 3 |
Describe failure modes and calculate resistances of bolts and set screws in shear. |
ASSESSMENT CRITERIA |
ASSESSMENT CRITERION 1 |
1. Failure modes of bolts and set screws in shear are described. |
ASSESSMENT CRITERION 2 |
2. Equations for calculating shear resistances are stated and explained in accordance with SABS 0162. |
ASSESSMENT CRITERION 3 |
3. Shear resistances are calculated for bolts and set screws in accordance with SABS 0162 (Part 1). |
ASSESSMENT CRITERION 4 |
4. The incompatibility of axial deformation in long bolted joints subject to double shear is described and illustrated. |
SPECIFIC OUTCOME 4 |
Describe failure modes and calculate resistances of bolts and set screws in direct tension. |
ASSESSMENT CRITERIA |
ASSESSMENT CRITERION 1 |
1. Failure modes of bolts and set screws in direct tension are described. |
ASSESSMENT CRITERION 2 |
2. The method of assessing additional direct tension in bolts and set screws due to the effects of prying is described, illustrated and calculated. |
ASSESSMENT CRITERION 3 |
3. Equations for calculating tension resistances in bolts and set screws are stated in accordance with SABS 0162-1: 1993. |
ASSESSMENT CRITERION 4 |
4. Tension resistances are calculated for bolts and set screws in accordance with SABS 0162-1: 1993. |
ASSESSMENT CRITERION 5 |
5. The use of the equation for bolts and set screws in combined shear and tension is explained and demonstrated in accordance with SABS 0162-1:1993, Clause 13.11.4. |
SPECIFIC OUTCOME 5 |
Describe the behaviour of slip-resistant joints and calculate resistances of joints. |
OUTCOME NOTES |
Describe the behaviour of slip-resistant joints and calculate resistances of joints where pre-tensioned bolts are used. |
ASSESSMENT CRITERIA |
ASSESSMENT CRITERION 1 |
1. Equation for calculating the minimum pre-tension value for bolts is stated in accordance with SABS 0162 - 1:1993 Clause 23.4.1. |
ASSESSMENT CRITERION 2 |
2. Surface preparation and coefficients of friction for a range of surface conditions are described in accordance with SABS 0162-1:1993. |
ASSESSMENT CRITERION 3 |
3. Equation for calculating slip resistances of joints is stated in accordance with SABS 0162 - 1:1993 Clause 13.12.2. |
ASSESSMENT CRITERION 4 |
4. The use of the equation for pre-tensioned bolts in combined shear and tension is explained and demonstrated in accordance with SABS 0162-1:1993, Clause 13.11.3. |
ASSESSMENT CRITERION 5 |
5. Tightening methods of bolts to achieve the required pre-tension are described in accordance with SABS 0162 - 1:1993 Clauses 23.5 and 23.6. |
SPECIFIC OUTCOME 6 |
Explain and discuss welding principles and weld processes. |
ASSESSMENT CRITERIA |
ASSESSMENT CRITERION 1 |
1. The principle of the welding arc is explained. |
ASSESSMENT CRITERION 2 |
2. Energy input from the arc is defined and calculated. |
ASSESSMENT CRITERION 3 |
3. The importance of protecting the molten weld pool is discussed. |
ASSESSMENT CRITERION 4 |
4. Different welding processes and methods for protecting the molten weld pool are discussed. |
ASSESSMENT CRITERION 5 |
5. The consequences of the effects of heat input on welds are explained. |
ASSESSMENT CRITERION 6 |
6. The importance of preheating and the rate of cooling in order to control hydrogen cracking of the heat affected zone is discussed. |
SPECIFIC OUTCOME 7 |
Describe and illustrate welded joints and weld types. |
ASSESSMENT CRITERIA |
ASSESSMENT CRITERION 1 |
1. Joint types are described and illustrated. |
ASSESSMENT CRITERION 2 |
2. Weld types and parameters are described and illustrated. |
ASSESSMENT CRITERION 3 |
3. Typical edge preparations for groove welds are explained and illustrated. |
ASSESSMENT CRITERION 4 |
4. The terms full penetration butt welds and partial penetration butt welds are defined and illustrated. |
ASSESSMENT CRITERION 5 |
5. Features of ideal weld preparations in relation to fit for purpose conditions are discussed. |
ASSESSMENT CRITERION 6 |
6. The importance of the welding position is discussed. |
SPECIFIC OUTCOME 8 |
Explain and illustrate weld defects. |
ASSESSMENT CRITERIA |
ASSESSMENT CRITERION 1 |
1. Typical examples of weld undercut defects are explained and illustrated. |
ASSESSMENT CRITERION 2 |
2. Slag inclusions are explained and illustrated. |
ASSESSMENT CRITERION 3 |
3. The causes and consequence of incomplete penetration and lack of fusion are discussed and illustrated. |
ASSESSMENT CRITERION 4 |
4. The causes and consequence of weld porosity are discussed. |
ASSESSMENT CRITERION 5 |
5. The occurrence and consequences of hydrogen cracking in the heat affected zone are discussed and illustrated. |
ASSESSMENT CRITERION 6 |
6. The causes and consequences of weld metal solidification or hot cracking are discussed. |
ASSESSMENT CRITERION 7 |
7. The causes and prevention of Lamellar tearing are explained and illustrated. |
SPECIFIC OUTCOME 9 |
Explain and illustrate weld strengths. |
ASSESSMENT CRITERIA |
ASSESSMENT CRITERION 1 |
1. Electrode classifications are discussed and an indication is given of their strengths and other characteristics in accordance with the American Welding Society (AWS) notation. |
ASSESSMENT CRITERION 2 |
2. Groove weld resistances are calculated and illustrated in accordance with SABS 0162-1:1993. |
ASSESSMENT CRITERION 3 |
3. Effective throat thickness of a fillet weld is defined and illustrated for different joint configurations. |
ASSESSMENT CRITERION 4 |
4. Fillet weld resistances are calculated in accordance with the internal force system occurring on the weld joint and illustrated in accordance with SABS 0162-1:1993. |
UNIT STANDARD ACCREDITATION AND MODERATION OPTIONS |
UNIT STANDARD ESSENTIAL EMBEDDED KNOWLEDGE |
UNIT STANDARD DEVELOPMENTAL OUTCOME |
N/A |
UNIT STANDARD LINKAGES |
N/A |
Critical Cross-field Outcomes (CCFO): |
UNIT STANDARD CCFO IDENTIFYING |
Identify and solve problems
Specific Outcomes 1. Describe failure modes and calculate resistances of bearing type bolts and set screws Assessment Criteria 1.1. Equations for calculating bearing resistances are stated and explained for different conditions in accordance with SABS 0162-1: 1993 1.2. Plate resistances are calculated for bearing type connections in accordance with SABS 0162-1: 1993 2. Describe failure modes and calculate resistances of bolts and set screws in shear 2.1. Shear resistances are calculated for bolts and set screws in accordance with SABS 0162 (Part 1) 3. Describe failure modes and calculate resistances of bolts and set screws in direct tension 3.1. The method of assessing additional direct tension in bolts and set screws due to the effects of prying is described, illustrated and calculated 3.2. Tension resistances are calculated for bolts and set screws in accordance with SABS 0162-1: 1993 4. Describe the behaviour of slip-resistant joints and calculate resistances of joints where pre-tensioned bolts are used 4.1. Surface preparation and coefficients of friction for a range of surface conditions are described in accordance with SABS 0162-1:1993 5. Explain and illustrate weld strengths 5.1. Groove weld resistances are calculated and illustrated in accordance with SABS 0162-1:1993 5.2. Fillet weld resistances are calculated in accordance with the internal force system occurring on the weld joint and illustrated in accordance with SABS 0162-1:1993 |
UNIT STANDARD CCFO COLLECTING |
Manage information
Specific Outcome 1. Describe and illustrate various types of bolts, set screws and pre-tensioned bolts and their mechanical properties in structural steelwork applications Assessment Criteria 1.1. The application of bolts and set screws in bearing, shear and direct tension is described and illustrated 1.2. The application of pre-tensioned bolts is described and illustrated 1.3. Classes of bolts, set screws and pre-tensioned bolts are listed in accordance with SABS 1700 1.4. Minimum Tensile Strengths, Minimum Yield Stresses and Proof Load stresses of bolts, set screws and pre-tensioned bolts are listed in accordance with SABS 1700 1.5. Minimum % Elongation at Fracture of bolts, set screws and pre-tensioned bolts are listed in accordance with SABS 1700 and its importance in relation to ductility is explained 2. Describe failure modes and calculate resistances of bearing type bolts and set screws 2.1. Failure modes of plates subject to bolts and set screws in bearing are described 3. Describe failure modes and calculate resistances of bolts and set screws in shear 3.1. Failure modes of bolts and set screws in shear are described 3.2. Equations for calculating shear resistances are stated and explained in accordance with SABS 0162 4. Describe failure modes and calculate resistances of bolts and set screws in direct tension 4.1. Failure modes of bolts and set screws in direct tension are described 4.2. Equations for calculating tension resistances in bolts and set screws are stated in accordance with SABS 0162-1: 1993 4.3. The use of the equation for bolts and set screws in combined shear and tension is explained and demonstrated in accordance with SABS 0162-1:1993, Clause 13.11.4 5. Describe the behaviour of slip-resistant joints and calculate resistances of joints where pre-tensioned bolts are used 5.1. Equation for calculating the minimum pre-tension value for bolts is stated in accordance with SABS 0162 - 1:1993 Clause 23.4.1 5.2. Surface preparation and coefficients of friction for a range of surface conditions are described in accordance with SABS 0162-1:1993 5.3. Equation for calculating slip resistances of joints is stated in accordance with SABS 0162 - 1:1993 Clause 13.12.2 5.4. The use of the equation for pre-tensioned bolts in combined shear and tension is explained and demonstrated in accordance with SABS 0162-1:1993, Clause 13.11.3 5.5. Tightening methods of bolts to achieve the required pre-tension are described in accordance with SABS 0162 - 1:1993 Clauses 23.5 and 23.6 6. Describe and illustrate welded joints and weld types 6.1. Joint types are described and illustrated 6.2. Weld types and parameters are described and illustrated 6.3. Typical edge preparations for groove welds are explained and illustrated 6.4. The terms full penetration butt welds and partial penetration butt welds are defined and illustrated 6.5. Features of ideal weld preparations in relation to fit for purpose conditions are discussed 6.6. The importance of the welding position is discussed 7. Explain and illustrate weld defects 7.1. Typical examples of weld undercut defects are explained and illustrated 7.2. Slag inclusions are explained and illustrated 7.3. The causes and consequence of incomplete penetration and lack of fusion are discussed and illustrated 7.4. The causes and consequence of weld porosity are discussed 7.5. The occurrence and consequences of hydrogen cracking in the heat affected zone are discussed and illustrated 7.6. The causes and consequences of weld metal solidification or hot cracking are discussed 7.7. The causes and prevention of Lamellar tearing are explained and illustrated 8. Explain and illustrate weld strengths 8.1. Electrode classifications are discussed and an indication is given of their strengths and other characteristics in accordance with the American Welding Society (AWS) notation 8.2. Groove weld resistances are calculated and illustrated in accordance with SABS 0162-1:1993 8.3. Effective throat thickness of a fillet weld is defined and illustrated for different joint configurations 8.4. Fillet weld resistances are calculated in accordance with the internal force system occurring on the weld joint and illustrated in accordance with SABS 0162-1:1993 |
UNIT STANDARD CCFO SCIENCE |
Demonstrate scientific and technological competence
Specific outcomes 1. Describe and illustrate various types of bolts, set screws and pre-tensioned bolts and their mechanical properties in structural steelwork applications 1.1. The application of bolts and set screws in bearing, shear and direct tension is described and illustrated 1.2. The application of pre-tensioned bolts is described and illustrated 1.3. Classes of bolts, set screws and pre-tensioned bolts are listed in accordance with SABS 1700 1.4. Minimum Tensile Strengths, Minimum Yield Stresses and Proof Load stresses of bolts, set screws and pre-tensioned bolts are listed in accordance with SABS 1700 1.5. Minimum % Elongation at Fracture of bolts, set screws and pre-tensioned bolts are listed in accordance with SABS 1700 and its importance in relation to ductility is explained 2. Describe failure modes and calculate resistances of bearing type bolts and set screws 2.1. Equations for calculating bearing resistances are stated and explained for different conditions in accordance with SABS 0162-1: 1993 2.2. Plate resistances are calculated for bearing type connections in accordance with SABS 0162-1: 1993 3. Describe failure modes and calculate resistances of bolts and set screws in shear 3.1. Equations for calculating shear resistances are stated and explained in accordance with SABS 0162 3.2. Shear resistances are calculated for bolts and set screws in accordance with SABS 0162 (Part 1) 3.3. The incompatibility of axial deformation in long bolted joints subject to double shear is described and illustrated 4. Describe failure modes and calculate resistances of bolts and set screws in direct tension 4.1. The method of assessing additional direct tension in bolts and set screws due to the effects of prying is described, illustrated and calculated 4.2. Tension resistances are calculated for bolts and set screws in accordance with SABS 0162-1: 1993 4.3. The use of the equation for bolts and set screws in combined shear and tension is explained and demonstrated in accordance with SABS 0162-1:1993, Clause 13.11.4 5. Describe the behaviour of slip-resistant joints and calculate resistances of joints where pre-tensioned bolts are used 5.1. Equation for calculating the minimum pre-tension value for bolts is stated in accordance with SABS 0162 - 1:1993 Clause 23.4.1 5.2. Surface preparation and coefficients of friction for a range of surface conditions are described in accordance with SABS 0162-1:1993 5.3. Equation for calculating slip resistances of joints is stated in accordance with SABS 0162 - 1:1993 Clause 13.12.2 5.4. The use of the equation for pre-tensioned bolts in combined shear and tension is explained and demonstrated in accordance with SABS 0162-1:1993, Clause 13.11.3 5.5. Tightening methods of bolts to achieve the required pre-tension are described in accordance with SABS 0162 - 1:1993 Clauses 23.5 and 23.6 6. Explain and discuss welding principles and weld processes 6.1. The principle of the welding arc is explained 6.2. Energy input from the arc is defined and calculated 6.3. The importance of protecting the molten weld pool is discussed 6.4. Different welding processes and methods for protecting the molten weld pool are discussed 6.5. The consequences of the effects of heat input on welds are explained 6.6. The importance of preheating and the rate of cooling in order to control hydrogen cracking of the heat affected zone is discussed 7. Describe and illustrate welded joints and weld types 7.1. Joint types are described and illustrated 7.2. Weld types and parameters are described and illustrated 7.3. Typical edge preparations for groove welds are explained and illustrated 7.4. The terms full penetration butt welds and partial penetration butt welds are defined and illustrated 7.5. Features of ideal weld preparations in relation to fit for purpose conditions are discussed 7.6. The importance of the welding position is discussed 8. Explain and illustrate weld defects 8.1. Typical examples of weld undercut defects are explained and illustrated 8.2. Slag inclusions are explained and illustrated 8.3. The causes and consequence of incomplete penetration and lack of fusion are discussed and illustrated 8.4. The causes and consequence of weld porosity are discussed 8.5. The occurrence and consequences of hydrogen cracking in the heat affected zone are discussed and illustrated 8.6. The causes and consequences of weld metal solidification or hot cracking are discussed 8.7. The causes and prevention of Lamellar tearing are explained and illustrated 9. Explain and illustrate weld strengths 9.1. Electrode classifications are discussed and an indication is given of their strengths and other characteristics in accordance with the American Welding Society (AWS) notation 9.2. Groove weld resistances are calculated and illustrated in accordance with SABS 0162-1:1993 9.3. Effective throat thickness of a fillet weld is defined and illustrated for different joint configurations 9.4. Fillet weld resistances are calculated in accordance with the internal force system occurring on the weld joint and illustrated in accordance with SABS 0162-1:1993 |
UNIT STANDARD CCFO CONTRIBUTING |
Understand contextual world-systems
Specific outcomes 2. Describe failure modes and calculate resistances of bearing type bolts and set screws Assessment criteria 2.1. Equations for calculating bearing resistances are stated and explained for different conditions in accordance with SABS 0162-1: 1993 3. Describe failure modes and calculate resistances of bolts and set screws in shear 3.1. The incompatibility of axial deformation in long bolted joints subject to double shear is described and illustrated 4. Describe failure modes and calculate resistances of bolts and set screws in direct tension 4.1. The method of assessing additional direct tension in bolts and set screws due to the effects of prying is described, illustrated and calculated 5. Describe the behaviour of slip-resistant joints and calculate resistances of joints where pre-tensioned bolts are used 5.1. Surface preparation and coefficients of friction for a range of surface conditions are described in accordance with SABS 0162-1:1993 6. Explain and discuss welding principles and weld processes 6.1. Energy input from the arc is defined and calculated 6.2. The importance of protecting the molten weld pool is discussed 6.3. Different welding processes and methods for protecting the molten weld pool are discussed 6.4. The consequences of the effects of heat input on welds are explained 6.5. The importance of preheating and the rate of cooling in order to control hydrogen cracking of the heat affected zone is discussed 6.6. Energy input from the arc is defined and calculated 7. Describe and illustrate welded joints and weld types 7.1. Features of ideal weld preparations in relation to fit for purpose conditions are discussed 7.2. The importance of the welding position is discussed 8. Explain and illustrate weld defects 8.1. Typical examples of weld undercut defects are explained and illustrated 8.2. Slag inclusions are explained and illustrated 8.3. The causes and consequence of incomplete penetration and lack of fusion are discussed and illustrated 8.4. The causes and consequence of weld porosity are discussed 8.5. The occurrence and consequences of hydrogen cracking in the heat affected zone are discussed and illustrated 8.6. The causes and consequences of weld metal solidification or hot cracking are discussed 8.7. The causes and prevention of Lamellar tearing are explained and illustrated |
UNIT STANDARD ASSESSOR CRITERIA |
N/A |
REREGISTRATION HISTORY |
As per the SAQA Board decision/s at that time, this unit standard was Reregistered in 2012; 2015. |
UNIT STANDARD NOTES |
Supplementary information
Specified requirements Specified requirements include legal and legislative specific requirements and are contained in one or more of the following documents: |
QUALIFICATIONS UTILISING THIS UNIT STANDARD: |
ID | QUALIFICATION TITLE | PRE-2009 NQF LEVEL | NQF LEVEL | STATUS | END DATE | PRIMARY OR DELEGATED QA FUNCTIONARY | |
Core | 48636 | National Diploma: Structural Steelwork Detailing | Level 5 | NQF Level 05 | Passed the End Date - Status was "Reregistered" |
2023-06-30 | CETA |
PROVIDERS CURRENTLY ACCREDITED TO OFFER THIS UNIT STANDARD: |
This information shows the current accreditations (i.e. those not past their accreditation end dates), and is the most complete record available to SAQA as of today. Some Primary or Delegated Quality Assurance Functionaries have a lag in their recording systems for provider accreditation, in turn leading to a lag in notifying SAQA of all the providers that they have accredited to offer qualifications and unit standards, as well as any extensions to accreditation end dates. The relevant Primary or Delegated Quality Assurance Functionary should be notified if a record appears to be missing from here. |
1. | Academic Institute of Excellence |
2. | Centurion Akademie |
All qualifications and part qualifications registered on the National Qualifications Framework are public property. Thus the only payment that can be made for them is for service and reproduction. It is illegal to sell this material for profit. If the material is reproduced or quoted, the South African Qualifications Authority (SAQA) should be acknowledged as the source. |