As this group is the fount of all engineering knowledge I wonder if anybody recognises the name 'Bullet AA' when related to HSS tool steel?
I inherited from my Father a box full of unused tool steel. There are various sizes which mostly have a ground finish and the manufacturers name or the specification etched on them. But there are several three inch lengths which are roughly 3/8" square with a black unground finish and with 'Bullet AA' cast(?) on one side. They appear very hard when touched on the grinder. They could have quite easily have come from the States as part of lend/lease.
I'm just curious to find out anything about them.
Thanks.
John H