Forged Shackle and Pin MT PT Exam Flaw Specimen (Inch Version) Carbon Steel Forged Shackle and Pin MT PT Exam Flaw Specimen Forged Shackle and Pin magnetic particle/Liquid Penetrant Exam flawed specimens. Geometry: 4.25" w/0.75" Pin. Flaws: 3, randomly placed Standard Tolerance: +/-0.150" (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.