Secure your grates to prevent displacement from heavy runoff flows, pedestrian and vehicular traffic, and to deter potential theft and vandalism when using the Dura Slope® ductile iron frame. Our ¼ in. X 1-1/2 in. Spanner head screws fasten down all Dura Slope® grates to channels and ProFit™ grate locks and provide additional security as screws can only be removed with a spanner drive bit (included). These screws have a sheared tip which allows them to easily thread into the receiving nut of the Dura Slope ductile iron frame. Each iron frame requires two DS-650 screws to secure the grate; one grate per frame. Use our 12 ct. bag of stainless steel screws to help an important part of your stormwater management product function effectively. Hassle-free limited lifetime warranty guarantees the NDS product is free from defects—or we’ll replace it.