Grummet A conventional grummet for securing flying wires to the top of flats. This cheap strong fitting should always be fixed with two machine screws and two wood screws. The grummet can be subjected to significant loads during the initial raising of the flats. Once raised, virtually all the strain will be transferred to the bottom rail. The finish is black powder coat. Size: 95 x 16 x 15mm. Fixings needed: 2 off No.8 or No.10 (4 or 5 mm) csk wood screws, 2 off 5 mm csk machine screws and tee nuts. As usual, during our testing we find the wood breaks well before the grummet is affected.