Thanks for posting that up. I've gone down this rabbit hole also, tried the smaller protrusion, still doesn't result in good flares. I think having a good die is key, and all the stuff I've seen so far is very low precision chinese made garbage. Or at least that's the stuff that I've gotten. I'll try indexing the protrusion to the OD of the tubing, as is mentioned in the comment below. I might give up on the plumbing style tool and just go with the eastman style in the end.

I had to learn the hard way on the truck iam doing now,but it works

good for clutch

I was having troubles too, but use different flaring tools to you. I set my protrusion as equal to line diameter.

$89.99 for 25 foot roll at O'reilly Auto Parts - but American Grease Stick Steel, Polyvinyl Fluoride (PVF) Brake Line - PAC325 is $26.99 for 25 foot roll. Reviews suck on this coated crap. The price on the Copper-Nickel Alloy for a 25 foot roll is crazy high. Maybe I'll just pinch off the rear brake line on my 1995 Chevy S10 Extended Cab LS 2.2L Standard Bed. I'll have to get the $ for the Copper-Nickel - I will not get the pre-bent because this crap of not being able to see where the line is leaking (rust pinhole before the soft tube - on the stock brake line is where it goes from running on top of the frame and bends down toward the rear axle so you can't even tell what exactly is going on - as where you cant get to, is where the hard tube goes to soft tube - then hard tube again to a splitter above the rear axle that splits the line to each rear brake. That's what I think anyways - there's 3 lines there - I'm guessing one is fuel to engine and one is fuel return line and maybe the brake line is just all metal but I can't tell unless I took the bed off with my topper on it and well - just spending the extra $ and changing the routing is going to be worth it. Do the lengths have to be an exact length?