CARRIAGE BOLT, INCH, NECK TYPE RIBBED, BASIC MATERIAL STEEL, MATERIAL GRADE GRADE 5, FASTENER FINISH ZINC PLATED, DIA./THREAD SIZE 3/8 IN.-16, FASTENER LENGTH 2 1/2 IN, FASTENER THREAD DIRECTION RIGHT HAND, FASTENER THREAD TYPE UNC (COARSE), RIB LENGTH 0.594 IN, HEAD HEIGHT 13/64 IN, TENSILE STRENGTH 120,000 PSI, FOR USE WITH TRAILER ROOF BOWS AND CROSSMEMBERS, PACKAGE QUANTITY 100