First don't shot the messenger
I hade a job in the lathe today which involved boring a hole 0.75 inches dia in a piece of 1 inch square stock 3 inches deep through not blind
I was using one of the tipped boring bars that are common in the merchants store ( Glanze omega at el ) my HSS bars are either to short or to big
as I stated with a 0.5 inch drill the boring bar was small and well extended the finish was terrible look like I had used a rusty nail ,
so on when a new tip the one they sell for steel no improvement tried it fast, tried it slow, tried it dry, tried it with cutting oil still a very bad surface , but as the finish size was getting near desperate measures was call for.
the hole dis. still required the middle size bar so a quick sort in the tip draw and I found some of those tips they sell for non ferrous metals nice and sharp with a good rake ( supplied from the dunstable outfit )
so one it went the cutter it just hissed and the finish was superb, by this time I could get in with the larger bar with the NON ferrous tip on the results were the same a good ridge free smooth finish in the bore
now I realise that these tips would not hold up for any heavy cuts but for finish work they work fine on Steel
I do not Know the grade but it aint EN1A it must be a form of GGQ ( Good ? General Quality ) unmachinium
again its one of the thing that goes against the book but it got me out of a mess today
may be worth a try next time I have some nasty lumpy steel to turn
Stuart