Some teams asked about the threads on the bit provided by Baker Hughes GE.
Do not modify the bit. Use the copper washer. You may modify the bit sub, if absolutely necessary.
They are 3/8” NPT, with standard taper of ¾” per foot. There is a countersink on the sub to prevent the last incomplete threads from crushing. They were chased by tapping and checking whether they mate flush.
Please do not modify the threads on the bit, and do use copper washer. If you have trouble matching the threads, you could modify the sub, even shorten it if you don’t have room.