Fastener Yokes XC and XF Offers high vibration resistance and a neat flush finish to connect beam ends to beam side.Through hole of 12.2mm must be drilled near the beam end to accept the yoke, use drill fixture stock-no. 326-5519.,To tighten the yoke, use a ball end Allen key.,Beams may be connected end to end, requiring two yokes, two M6 x 50 caphead screws (DIN912,ISO4762) and two M6 hex nuts per joint.