[mentorDon]

I pulled the gear off the Keyang and it not the same as the amequipment.com. The keyang has a smaller splined end used for the drive instead of the 2 flats. I also was checking on the dimensions of the gear on their site and the numbers don't match to any standard gear, English or metric. The Keyang gear does appear to have a DP of 12. I plotted 3 gears out using Mechanical Desktop, DP12, M2 and M2.25. The DP12 fits very well to the plot. The other two closest metric plots are smaller or larger. The next best thing would be to calculate a center to center distance with the Keyang and another DP12 gear and make a test bar with pins to make sure there is not any binding during rotation.