Surface : Blackened. - Thread Dia : M6 M8 M10 M12 M14 M16 M18 M20 M22 M24 M27 M30. 【Socket Head Cap Design】: Tight threads are clean, accurate, and smooth, not prone to warping during rolling. The Socket head cap design can be easily installed with a hexagonal wrench, and it is not easy to slip out.
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