This document discusses quality inspection and testing procedures for arc stud welding of metallic materials. It outlines several acceptance criteria and testing methods, including visual examination of stud shape and size, bend testing to check for cracks below the elastic limit, tensile testing to ensure the stud's nominal strength is reached, torque testing of nuts on studs, and macro examinations and radiographic examinations to evaluate weld penetration depth and internal imperfections. Regular production tests are recommended to qualify welding procedures and ensure process control.

1. Quality Inspection and Testing of Arc stud
welding (metallic materials)
Sai Anjaneya

2. Contents
▪ Introduction
▪ Welding procedure qualification
▪ Examination and testing
▪ Acceptance criteria
▪ Process control
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3. Introduction
▪ The purpose of arc stud welding is to weld
predominantly pin-shaped metal parts to metal work
pieces.
▪ Applications
– Vehicle manufacture
– Bridge building
– Manufacture of household appliances etc.
▪ The quality of a stud weld depends not only on
strict compliance but also on the correct function
of the actuating mechanism (e.g. welding guns).
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4. Video
4Source: https://youtu.be/Ljz6twH-Pc4

5. Welding procedure qualification
▪ In principle, the following methods of qualification
are permitted
– welding procedure test
– pre-production tests
– previous experience
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6. Examination, Testing and Acceptance criteria
▪ Visual examination
▪ Bend testing
▪ Tensile testing
▪ Torque test
▪ Macro examination
▪ Radiographic examination
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7. Visual examination
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In drawn arc stud welding with ceramic ferrule or
shielding gas visual examination is used for assessing
the following:
• The uniformity of the shape and the size of the
collar
• Location, length and angle of the stud after welding

8. Acceptance criteria for visual examination
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9. Bend Testing
▪ The test serves as a simple bench test for
approximate checking of the chosen welding data. In
the test, the weld is subjected to bending in an
undefined manner.
▪ The studs are stressed by applying a bending moment
below the elastic limit
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Key
1- stud
2- work piece
3- tool
α-bending angle

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 The tool diameter can be chosen freely by the
manufacturer, depending on the stud spacing.
 The drive dimension depends on the tool
Bending moments based on stud diameter

11. Acceptance criteria for Bend Testing
▪ A weld passes the test if no cracks are found in
the weld after bending of the stud through 30° or
60°.
▪ If a low-deformation fracture occurs in the heat-
affected zone, the weldability of the materials
shall be checked (e.g. tendency to hardening).
▪ Cracks which arise from the thread bottom are
disregarded.
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12. Tensile Testing
▪ By using a suitable tension device the welded studs
are pulled axially until fracture.
▪ The test only applies to studs by application ≤ 100
degrees Centigrade
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Key
1- stud
2- steel nut
3- washer
4- sleeve
5- collar
6- work piece

13. Acceptance criteria for Tensile Testing
▪ A fracture in the weld area is not permitted.
▪ Fractures within the weld zone are only permitted
if the nominal tensile strength of the stud
material is reached.
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14. Torque test
▪ Weld resistance is checked by applying a torque T
on a cap nut fully tightened on the stud.
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Key
d - Stud diameter
h - Length of the threaded
part of the nut
t - Thickness of plate
T - torque

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Minimum values of required torque on mild steel

16. Macro examination
▪ The macro examination serves to check the shape and
depth of the penetration.
▪ The assessment shall be carried out with a maximum
of tenfold magnification.
▪ For the specimen, a stud which has passed the bend
test may be chosen.
▪ Imperfections with dimensions larger than specified
are not acceptable.
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17. Radiographic examination
▪ The radiographic examination serves to check the
weld area for internal imperfections.
▪ Required for the welding process, drawn arc stud
welding with ceramic ferrule or shielding gas above
d > 12 mm for applications ≤ 100 °C, when
tensile tests are not carried out.
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18. Process control
▪ Before, during and after production, tests shall
therefore be performed.
▪ The various tests are as follows:
– production test
– simplified production test
– production surveillance
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19. Production Test
▪ Production tests shall be performed by the
manufacturer before the beginning of welding
operations on a construction or a group of similar
constructions, and/or after a specified number of
welds.
▪ The following examinations and tests shall be
performed:
– visual examination (all studs)
– bend testing (five studs)
– macro examinations of two different studs
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20. References
▪ http://www.betawelding.ir/en/images/ISO_14555.pdf
▪ ISO 14555
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