Carbide tipped 0.635” drill bit.
These bits are custom made for Needham Ag and feature a serrated carbide cutting tip, with 3 flats on the other end to stop them spinning in the chuck. They typically drill around 6-10 of the 90 series extended wear seed boots or around 50-100 standard wear 50, 60 or 90 series seed boots.
A heavy drill press (or preferably a mill) with a good vice is essential to eliminate all vibration, especially when drilling out the John Deere extended wear seed boots (part numbers end in number 24 or 25).
A 1/2″ chuck is required with this drill bit and they need to be turned at 500-600 RPM with no lubrication or coolant.