for a die grinder they wouldnt be cheap
https://www.amazon.com/YUFUTOL-SC-5L6-Tungsten-Carbide-Burr/dp/B06X1G6VH4/ref=sr\_1\_19?crid=EZ9VV8NU2C3K&keywords=long+die+grinder+bit&qid=1677046646&sprefix=long+die+grinder+bi%2Caps%2C375&sr=8-19