Jeff,

The machinist at WRM took the first cut deep enough to get under the hex flats. He was very experienced and was not afraid of taking a heavy cut. We normally make bolts out of 12L14 and kept a stock of hex bars of various sizes to accommodate this. There have been times that bolts were made from round stock, but cutting the hex head is a slow process requiring an additional set up on another machine, so this was normally avoided.

On the tapered bolts, they were turned between centers using a three jaw chuck just to drive the hex. The taper attachment was preset to the proper taper. The bolts could be taken out of the lathe and trial fit. Then quickly put back in the lathe for another cut if required.

Thanks for the info!