NATIONAL NAIL 93098 Pro-Fit 0093098 Square Cut Masonry, 4D X 1-1/2 in L, 0.109 in Shank Hardware-Nails. Use PRO-FIT cut masonry nails to attach wood to cinder block, mortar joints, brick walls, and fresh concrete in interior projects. The nails feature a blunt point and tapered design that keep the concrete from splitting during penetration. Additionally, the tapered shank offers pull-out resistance. Cut masonry nails are heat-treated to increase resistance to bending when driven into hardwood or masonry