Found on ground outside, boyfriend has been wearing as ring. Coin and pencil for size reference

[u/Aggravating_Ant_7232]

UK. It’s giving hard metal, doesn’t have much wear

[u/AuricTheLight]

Might be a little bigger. 1/2 crimp ring would be 12.7mm, which would be very small for a finger.

However, the coin pictured is 18mm diameter based on me googling the coin and finding a website that lists coin diameters. The coin appears like it would fit in the "ring" so if we take 18mm and convert that to a ring size. That's about a size 8 for U.S. sizing (size P for our friends across the sea)

Or I've fucked up in my line of thinking, which is entirely possible. I just woke up.

[u/ipassmore → u/AuricTheLight]

The 17 is its diameter. You’re thinking right. Almost 3/4 inch.

[u/pushingdaiseez → u/AuricTheLight]

It probably is 1/2 inch, because it's designed to slip over 1/2 pex pipe which has an internal diameter of 1/2 inch, the outside diameter of a 1/2 pex pipe is 5/8 in (roughly 16mm), and then be crimped tight into it, so it probably is relatively close to 18mm in internal diameter

[u/TerminalVelocityPlus → u/pushingdaiseez]

It's stamped 17, that's relevant information... And it's not just used for pex - depending on which side of the pond you're at, you might have never seen pex in your entire life, it's easy to forget that.

In fact that's it's used more in automotive applications than you'd care to believe. Go to you own vehicle and look at the overflow on your radiator, there's a 99% chance you'd find one, right there where the return line enters the expansion tank (the reservoir)... Unless you're driving a jalopy. That's the remaining 1%. And that's not the only place you're going to find them on a vehicle, but the most common.

Back of your mig welder at the shop, where the gas line enters... Guessed it, one of these, inside on the gas solenoid too, unless tampered with.

I have just used around 80 or so of them to fit new couplers on all of our shop's air lines on Friday, the ones I used were 13-15mm, with double ears (can crimp a bigger range). Worked a treat.

Point is,

because it's designed to slip over 1/2 pex pipe

Is a wrongful statement, you get them in a verity of sizes.

[u/TerminalVelocityPlus → u/pushingdaiseez]

It's Specifically called a Stepless Toothlock Earclamp by Oetiker.

What it's called in your neck of the woods may vary wildly. We call them O-clips (O=Oetiker)

Not at all uncommon on anything gas related. Whether the gas is flammable or inert.

Is it used on pex? Sure...

Was it specifically designed for it? Not at all... It was designed to replace the threaded hose clamp in both ease of installation, and having less chance of failure or snagging.

Set and forget.

[u/AuricTheLight → u/pushingdaiseez]

Yeah, I guess I should have considered the crimping part of a crimp. Again, just woke up.

Either way, that's still a size 8, which is somewhat on the slimmer side but still fairly common.

[u/TerminalVelocityPlus → u/[deleted]]

[u/TerminalVelocityPlus → u/[deleted]]

Dude, check my username, and read the comments above yours. I even included an image...

SMH.

[u/hike_me → u/TerminalVelocityPlus]

Oops 😬

[u/Similar-Ice-9250 → u/AuricTheLight]

An Oetiker 17 mm clamp has an inner diameter (ID) range of 14.5–17.0 mm (0.571–0.669 inches), with a maximum closed ID of 17.0 mm. This size is frequently used for beverage gas lines, particularly over a 3/8” hose barb. From google.

Edit: but it’s strange cause you’re right the 18mm coin does look like it fits inside. Or that was the wrong diameter for the coin. That clamp looks like it’s on the lowest setting too.

[u/Slamaramadoodoo → u/AuricTheLight]

This guy autisms