Joist hangers are designed to provide support underneath the joist, rafter or beam to provide a strong a connection. Simpson strong-tie offers a diverse line of hangers to handle almost any application with top flange, concealed flange and field skew able and slope able options. The hurricane tie series features various configurations of wind and seismic ties for trusses and rafters. Install with 8D common nails or #9 x 1-1/2 in. Strong-drive sd screws.