From old stock. Had some rust and staining and I cleaned it up a bit. Has never been on a machine.Buyer will receive the sprocket shown. 40 Chain Number 1 Strand 18 Teeth Without Hardened Teeth B Sprocket Style DESCRIPTION Maximum bores shown will accommodate standard keyseat and setscrew over keyseat. Slightly larger bores are possible with no keyseat, shallow keyseat, or setscrew at an angle to keyseat. FEATURES Tolerances meet or exceed ANSI standards Manufactured of high carbon steel Precise machining and processes ensure consistent finish and high quality Bores are concentric to pitch line, minimizing run out SPECIFICATIONS HUB DIA. 2.31 in HARDENED TEETH Without Hardened Teeth LENGTH THROUGH BORE 1 in INCH/METRIC Inch OUTSIDE DIA. 3.1400 in CONSTRUCTION Solid MATERIAL Steel BORE RANGE [MAX] 1 1/2 in PITCH DIAMETER 2.880 in HUB LENGTH THRU 0.716 in CHAIN NO. 40 WIDTH ACROSS TEETH 0.28 in CHAIN PITCH 1/2 in CALIPER DIAMETER 2.57 in NO. OF TEETH 18 SERIES B MARTIN NO. 40B18 OUTSIDE DIA. [MIN] 3.1400 in BORE TYPE Reborable BORE RANGE [MIN] 5/8 in NO. OF STRANDS ACROSS 1 BORE STYLE Minimum Bore SPROCKET STYLE B KEYWAY No Keyway or Setscrew PITCH DIAMETER [MIN] 2.880 in WEIGHT 1.22 LB EAN OR UPC 697950004426