Gypsum Screw - (6 x 2-inch)

Cavalry gypsum screws in gauge 6, two inches long - the longest of the common lengths. The extra reach is for work where the screw has more to travel through before it finds anything solid: a second layer of board over a first, board over battens or packing, thicker fire-rated sheet, or a ceiling being brought down level over an uneven soffit. Using the standard 1.5-inch in those situations gives a screw that grips the board but barely bites the timber, and boards fixed that way work loose and crack along the joints months later. Bugle head, so it sets flush and dimples the paper for filling; coarse thread, so it drives without a pilot. Buy alongside the shorter lengths rather than instead of them - overlong screws in thin board hit services.