Fasten-It Ltd, Fasten It Ltd, FastenIt are a British manufacturer and supplier of quality products for the UPVC Roofline, door and window fitting industries. Products include polymer headed pins, polymer headed nails, plastic headed pins, plastic headed nails, polypin, polypins, polynail, polynails, screws, nails and baypole screws to name but a few. Based in Northampton, the Midlands.