I will be using ear clamps next week for the first time, specifically small stainless steel "single ear" Oetiker brand clamps, vs double ear clamps. It will be for a light duty, one atmosphere pressure fluid application, for permanently clamping Tygon tubing to 5/16 in brass barbs.

But I have a few questions:

What is the difference in usage between single vs double ear clamps for a similar clamp size, and when would you use one vs the other?

How do you know when you've applied "enough" clamping force through your hand applied ear clamp pliers ? Is it determined by feel like a lot of things in automotive work, or by some level of deformation between the clamp band and the hose or tubing, a standard remaining gap in the finished ear clamp pinch, or something else ?

Is the Oetiker Brand the final word in ear/pinch clamps, vs other brands, vs Asian or other no-name ear/pinch clamps ?

Any other information or advice appreciated, particularly as it relates to automotive work, other things being equal.

My experience with Oetiker clamps is in the industrial world versus the automotive. We used primarily the double ear clamps but were dealing with much higher pressures. Oetiker is the benchmark for pinch type clamps and the tubing always failed before the clamp would allow it to blow off the fitting. Regarding pinch pressure if the clamp is the correct size for the tubing it will be properly clamped when the ear is fully compressed and the internal edges of the ear meet.

Well I got my Oetiker clamps in the mail, and applied two different sizes for the exact same connections. Funny thing the bigger clamp left a larger ear gap than the smaller clamp. Would have thought the opposite result. Not sure how that worked, maybe difference in gauge of band, can't tell. But an outstanding connection nevertheless, super compact, clean, permanent, and sharp looking. I ordered extra in other smaller and larger sizes since I couldn't find a kit assortment from the company itself that didn't include the clamp tool.

My experience with them has been with the generic ones for sprinkler lines, and the PEX brand ones for plumbing.

First experience with the sprinkler line ones I just used the $10 pliers they sold with the clamps at the irrigation supply store. They would pinch until both sides of the clamp touched on that poly sprinkler pipe.

I tried the $10 pliers on the pex clamps with PEX tubing and they couldn't get them near the specification on the package (I think it was 1/8”). I didn't want to risk it on indoor plumbing so I sprung for the ratcheting PEX pliers. They crimped it down like nothing.

Not sure if the difference is the pipe, the clamp or both, but there's definitely different varieties.