34 Pa. Code § 47.262
The posts or uprights shall be fastened to the floor or structural frame by rivets, tap bolts or through-bolts with plates or washers in the case of steel construction or by through-bolts with plates or washers in the case of wood construction or by angle post sockets. When fastened to wood, the bolts shall be so arranged that no two bolt holes are in line with the grain of the wood. If angle post sockets are used, the throat of the socket shall have a depth of not less than four inches, the post shall be fastened to the socket by at least two bolts, and the socket shall be riveted to the floor or structural frame in the case of steel construction or through-bolted to the floor with plates or washers in the case of wood construction. The socket shall be secured to the floor or structural frame by at least four bolts or rivets. Reference should be made to Plate 2-B, C, D of the Appendix.
34 Pa. Code § 47.262