BlackStar 80BS53 1 7/16 K2S - 80 Pitch Finished Bore Sprocket - 53 Tooth - 1-7/16" Bore Taper-Lock Bushing What does the 5M in

What does the 5M in 1730-5M-15 mean

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Number of Teeth 80 Width 170mm

12/C180 has a top width of 11

BlackStar 80BS53 1 7/16 K2S - 80 Pitch Finished Bore Sprocket - 53 Tooth - 1-7/16" Bore Taper-Lock Bushing What does the 5M inThe BlackStar 80BS53 1 7 16 K2S is a 80 pitch Finished Bore roller chain sprocket with 53 teeth, precision manufactured from SAE 1045 steel and features machine cut tooth profiles for smooth, reliable chain engagement. This sprocket has a 1 7 16" bore with keyway and set screws and is ready for immediate installation. Specifications Part Number 80BS53 1 7 16 K2S Chain Pitch 80 Number of Teeth 53 Bore Size 1 7 16" Minimum Bore 1 3 8" Maximum Bore 2 15