Used when constructing drywall track and ceiling track systems to stitch the track together (Max. 3.0mm) without the need to pre-drill a hole. Features TimCo Wafer Head Self Drilling Screws PH2 for Drywall. A Phillips Wafer Head Self Drilling Screw for Dry Wall These Wafer Head fixings, suitable for dry wall are CE approved TO EN ISO 14566:2008 standards. Manufactured to SAE J48-1979 specification so that surface hardness up to 650 HV is achieved. Specification Size - 4.2 x 25mm Boxed in quantities of 1000