Are you talking about rubber hoses from frame to front wheel cylinder and rear frame to axle Tee?
If they are sold by a reputable vendor they are OK. I've not seen brake lines less than
3/16. Those are metal. I assume you are measuring the hole in the fitting that is swaged to hose? Don't think you can get an accurate measurement there unless you use a drill bit as a gauge.
Bottom line, I wouldn't worry about it, the pressure will be there.


Right is right, even if everyone is against it, and wrong is wrong, even if everyone is for it. - William Penn