STAINLESS STEEL HEXAGON HEAD BI-METAL STITCHING TEK 2 SCREWS WITH 16MM SEALING WASHER

Hexagon Head Bi-Metal Stitching Tek 2 Screws with 16mm Sealing Washer — This is the hex-head alternative to the button-head, hexalobular-drive stitching screw covered elsewhere in this range, doing exactly the same job of joining overlapping roofing or cladding sheets along a side lap rather than fixing the sheet to the structure beneath. The Tek 2 point only ever has to drill through two thin layers of sheet at the lap, which is why this stitching family uses the lightest point rating in the Tek range rather than stepping up to Tek 3 or Tek 5, which exist for thicker single-skin or structural steel fixings. What sets this version apart is the hex head, driven with a socket rather than a screwdriver bit, paired with a larger 16mm sealing washer rather than the 12mm washer on the button-head equivalent. Practically, that's a choice about installer preference and lap-seal area rather than a difference in drilling or jointing performance: a hex head with a socket driver suits installers used to driving with a nut driver or socket set across a job, while the larger washer spreads slightly more sealant area across the lap. Bi-metal construction applies as it does throughout the Tek range - a stainless body and thread resist the sustained weather exposure a roof or wall lap sees over the building's life, while the hardened carbon-steel point handles drilling the two sheet layers without a pilot hole. It's worth being clear about what this screw isn't: it doesn't carry the sheet's primary fixing load into the purlins or rails, so it should never be substituted for a halter or structural Tek 2, 3, or 5 fixing, only used alongside one to close the side laps between adjacent sheets. Choosing between this and the button-head version comes down to head and washer preference; choosing a stitching screw at all rather than a structural fixing depends on whether the job is joining sheet to sheet or sheet to structure.

FAQs
How does this differ from the Hexalobular Button Stitching Screw with a 12mm washer?
Both are Tek 2 stitching screws for side-lap jointing with identical drilling and jointing performance; this version has a hexagon head driven by socket and a larger 16mm washer, while the other uses a lower-profile button head, hexalobular drive, and smaller 12mm washer.

Is this a structural fixing into the building frame?
No. It secures sheet to sheet at the side lap only; a halter or structural Tek fixing is needed to carry the sheet's primary load into the purlins or rails.

Why choose the hex head version over the button head version?
Mainly installer preference for a socket driver over a screwdriver bit, and where a slightly wider washer and sealed area at the lap is wanted.