Rub collar for 3/4" Arbor only! Due to size, Furnished with only one 1/2" X 3/4" Bushing, #972, (D) diameter 2-5/8, (D) bore 1/2 & 3/4, (b) Cutting height 3/8, (r), radius 3/16, Description 3/8 Flute, optional rub collar c-025, 972 carbide Tipped 3-Wing flute (convex) 3/8 Flute x 3/16 radius x 2-5/8 dia x 3/8 x 1/2 & 3/4 bore