Actually SAE stuff isnt bad. Your just not used to it. A 45° inverted automotive double flare is an industry standard. You will find these in metric and in SAE. The reason i mention 45° is that aircraft fittings, and aviation type fittings you see on souped up cars are 37° and do not interchange.
If i had to guess i bet a metric 45° inverted double flare forming tool could be used with success on SAE tubing. Btw the adjuster bolt on my denso alternator is a 13mm. Perfect size as a 1/2" wrench fits it. LOL.
Harley Davidsons would drive you nuts as well then everything on even the new ones is SAE except for the front forks.
