I have up for auction 4 -1 1/2 " cross carbide inserts rock drilling DRILL BITs.They thread on to a 7/8" shaft and I believe they are a 6 thread.They were made by Ingersall Rand and they are new old stock.I have about a box in a half of these bits so if you are interested in them let me know.They are still in the original boxes and if you want them all I will ship them in these boxes.The I.R. No. is 114