trun sup dim

Trunion support beam

Holes large enough for mounting screw and washer, 12 mm deep. Smaller 1/4" hole all the way through błock

Cavity for 1/4" T-nut to be mounted just below flush with the surface.

Alternately, you can use a threaded insert instead of a T-nut.

Cutout to provide clearance for trunions. Beam length and trunion spacing are both 28.0 cm, so it's good to make a clearance cut so the trunions won't rub against the beam.