PRAD SYSTEM PRAD system Solution tool PRAD system Standard blank dimension table (for Japan) Main size designation and specification ① ② ③ ④ ⑤ STI ⑥ STI metric unified whitworth sewing screw (metric) (unified) M8×1.25 5/16-18UNC W5/16-18 5/16-20UN STI_1/4-20UNC M8×1 5/16-24UNF STI_M6×1 5/16-28UN STI_1/4-28UNF M8×0.75 5/16-32UNEF M9×1.25 M9×1 M10×1.5 3/8-16UNC W3/8-16 STI_5/16-18UNC M10×1.25 3/8-20UN STI_M8×1.25 M10×1 3/8-24UNF STI_M8×1 STI_5/16-24UNF 3/8-28UN M11×1.5 M11×1.25 STI_M9×1.25 M11×1 STI_M9×1 STI_3/8-24UNF M12×1.75 7/16-14UNC W7/16-14 M12×1.5 7/16-16UN STI_M10×1.5 STI_3/8-16UNC M12×1.25 7/16-20UNF STI_M10×1.25 M12×1 7/16-28UNEF STI_M10×1 M13×1.75 1/2-13UNC W1/2-12 M13×1.5 1/2-16UN STI_M11×1.5 M13×1.25 1/2-20UNF STI_M11×1.25 STI_7/16-20UNF M13×1 1/2-28UNEF M14×2 M14×1.5 STI_M12×1.5 STI_7/16-14UNC M14×1.25 STI_M12×1.25 M14×1 STI_M12×1 M15×2 9/16-12UNC W9/16-12 STI_M12×1.75 M15×1.5 9/16-16UN STI_M13×1.5 9/16-18UNF M15×1.25 9/16-20UN STI_1/2-20UNF M15×1 9/16-24UNEF 9/16-28UN M16×2 5/8-11UNC W5/8-11 STI_1/2-13UNC 5/8-12UN STI_M13×1.75 M16×1.5 5/8-16UN STI_M14×1.5 5/8-18UNF M16×1.25 5/8-20UN STI_M14×1.25 M16×1 5/8-24UNEF 5/8-28UN STI_M14×2 M17×1.5 STI_9/16-18UNF M18×2.5 M18×2 STI_9/16-12UNC M18×1.5 STI_M16×1.5 M18×1.25 STI_5/8-18UNF * Corresponding pitches meet with the pitches of other kinds. * Concerning Hand of threads, both right and left are applicable in the same blank. * Concerning the kind of taps, SP, PO, HT, ROLL are applicable in the same blank. * Concerning applicable thread limits, maximum applicable thread limits for metric coase threads are listed. PRAD-33