having made literally thousands of flares manually I tried every type known
Snapon Imperial Eastman Ridgid Craftsman and none works like this one.
It was around $300 which is more than alot of guys want to pony up,but does so much more than simple flares.I have no problem doing 3/8 double flares on stainless tubing.
Try that with your manual one.
http://www.mastercool.com/pages/flaring_tools.html
One of the keys to making a good slip free flare is to clamp the holding fixture in the vise as close to the hole youre using as possible. This prevents the tool from spreading open and having the tubing slip.Dont use the end that is made for clamping in vise as the holding fixture will slip because of flex.Those bolts on the end will work for only very small flares.
If in the field use 2 pair of vise grips one on each side of the fixture.
The tool is high quality and made in USA.
Customer support is top notch too.