Huc410, 4x10 concealed flange hanger, designed for schools & other structures requiring additional strength, longevity & other safety factors, smooth lines make it attractive for exposed applications, can be installed using round holes only, or filling round & triangle holes for maximum load values, 14 gauge galvanized steel, minimum value install with fourteen 16d nails into header, six 10d nails into joist, maximum value install with eighteen 16d nails into header, ten 10d nails into joist.