The inspection method according to the “required quality” is required. For typical objects, however, there are methods for measuring nugget diameter etc. by cross section macro-test, and for measuring the tensile strength, there are tensile stress called TSS and cross-hair tensile strength called CTS.
The actual work can not be used in case of these measuring method.In such cases, chisel test, peel test, or torsion test may be adopted to facilitate on-site testing.
These measuring methods are also specified in JIS and should be used as a reference.
JIS Z 3140: Methods and Criteria for Inspecting spot welding Section
JIS Z 3144: Field Test Methods for Spots and projection welding
JIS Z 3139: How to cross section test spots, projections, and seam welding
JIS Z 3136: Test Piece Dimensions and Test Methods for Shear Tests of Resistive Spots and Projection welding Joints
JIS Z 3137: Test Piece Dimensions and Test Methods for Resistive Spots and cross tension test of projection welding Joints
JIS Z 3138: How to fatigue test spot welding joints