STRONG ARM SHELF BRACKETS – This utility shelf bracket is designed with superior strength. Brackets are sized to fit standard lumber widths. Brackets are angled slightly over 90deg. ot keep items on the shelf. Brackets are punched for #7 wood screws. Six screw holes per bracket are for extra holding power. Meets ANSI/BHMA standards 156. 16 Grade 2. Deep rib design gives extra strength.