For fastening lumber to any type of concrete or masonry work. Predrilling may be necessary in some applications. For best holding power, choose a length that will penetrate into the masonry. Solid blows at right angles provide the best results. For fastening lumber to any type of concrete or masonry work Pre-drilling may be necessary in some applications Finish: temper hardened Flat countersunk head Diamond point Fluted shank Gauge: 9 Head: 5/16\”