Let me start by saying I'm not an insert guy . I like my hss tools , I like to grind them , and I 'm the proud owner of a clarkson MKIII t&c grinder . Never needed inserts , and hardly use them . That said , I recently got some lathe tools with ccgt0903 inserts . CCGT is ment to be used on alloy's . So I gave them a try . And I must say , I'm speechless with the way they perform . These inserts have a high positive rake , are rasor sharp , and leave a bright shiny finish when turning aluminium . Even the worst alum I have ( the home cast variety ) machines to a very acceptable finish , with no sticking of the chips to the tool . Thought I'de share that . Pat Btw I wonder what material these inserts are made of . It doesn't look like carbide .