YEP Trevor im sure you are right about the technicalities of the material, i just machine it ! , i had to learn it as part of my degree but like Maths 3 i took great delight in forgetting all of it !

Only thing i would say about your authoritive post is that you said:


" is correct about machining,
high speeds with negative / neutral rake"

depends what you mean HIGH SPEEDS ? on a bush id of that size i would not go above say 250-300 rpm reaming ( i used spiral reamers ) on a production auto ( although technically not right i would flood it with Ilocut 437 NOT soluble! , feed something like 4 thou per rev , probably just doing a one off on a center lathe i would drop that down even further to say 150-200 using HAND FEED you have a good feel if it starts hogging in and less chance of it heating up

I would do the rest of the turning. Boring at 800-1000 rpm same feeds
I loved doing production work like these on CUSTOMER SUPPLIED material , my line was simple, "there are so many bronzes i dont want the risk of incorrect material and its very expensive so YOU supply"

IN reality i just wanted the swarf hahaha .......had one customer ask for the swarf back so i told him sure but i charge $150 for a machine clean down after brass/bronze (it must be cleaned thoroughly or you get too many slinters next set up! , you still want it ? he didnt and just laughed and said oh well it was worth a try ..i further explained that I dumped at least $20 of ilocut with the swarf ...sure i spin it but you never get all the cutting oil back


PS I love the idea of "sweating " the liner in i thought about that but didt have any silphos but it would be the definitive job...i do pity the next comedian who didnt realize it had been sweated in and tried to get it out .......maybe a note with an engraver on the open end of the bush ?


"There's the way it ought to be and there's the way it is" (Sgt Barnes)