ASP Ltd are one of the UK's leading screw suppliers. We offer everything from concrete and wood screws, to solar panel fixings. Our high quality products are sold in bulk at the most competitive trade prices. We offer free shipping on all orders over £100. ASP Ltd are one of the UK's leading screw suppliers. We offer everything from concrete and wood screws, to solar panel fixings. Our high quality products are sold in bulk at the most competitive trade prices. We offer free shipping on all orders over £100.