Forged Shackle and Pin MT PT Exam Flaw Specimen (Metric Version) Carbon Steel Forged Shackle and Pin MT PT Exam Flaw Specimen Forged Shackle and Pin magnetic particle/Liquid Penetrant Exam flawed specimens. Geometry: 108mm w/ 19mm Pin. Flaws: 3, randomly placed Standard Tolerance: +/-4mm. Documentation: NDT Verification Reports, C of C, CAD Drawings and Test Sheets. Material: Carbon Steel. Customized Calibration Test Block and Flaw Specimen also available.