Magnum intake drilling plate project

Made 2 steel pipe nipples from a steel grease gun tube. Correct size and thread.
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Grease guns normally/ used to be 1/8 pipe thread. In other words 1/8 NPT "It might be" that some of them you run into nowadays are some sort of metric. Japanese pipe fittings used to be a bit smaller than US NPT. For example, if you bought an SW oil pressure line kit, it came with adapters from the US fittings to Japan, which were smaller.