Park Tool HCW-18 Bottom Bracket Spanner The double-ended HCW-18 Bottom Bracket Spanner is a double ended wrench for for use with some one-piece carbk/bottom braacket systems. One side fits three-notched fixed side cones with an outside diameter between 42mm and 46mm, while the opposite side fits slotted adjusting cones with an outside diameter of 44mm or less. Features Related Articles: BOTTOM BRACKET SERVICE: ONE PIECE Manufacturer's Part No: HCW-18 UPC: 763477004185 | Park Tool | Hcw-18 Bottom Bracket Spanner Hcw-18