In my new apartment, I moved in to find the water dispenser in the fridge is not working. I quickly diagnosed the issue by moving the fridge away from the wall and finding that there is a water line coming out of the wall with a shut off valve at the end, but it is not connected to the fridge. A quick try convinced me that I cannot directly connect the free male end of the shutoff valve with the male end I found on the back of the fridge. The issue seemed pretty standard, as I found many online sellers selling an "ice-maker supply line" with female compression ends that seemed like they would do the job.
When this part arrived, I was able to connect it to the fridge with minimal trouble, but it would not connect to the shutoff valve no matter how hard I tried. Eventually, I discovered that even though the nut seems like it is the right female counterpart to the male threading on the free end of the shutoff valve and is almost a correct fit, it is not. In fact, the two sides of the shutoff valve are not equivalent, with the side connected to the water line coming from the wall being the correct counterpart to the female ends of the "ice-maker supply line" I ordered. So, it seems that I need to get an adapter to go between the two, but it would help to know what exactly I am looking for, since I can't take the shutoff valve with me to the hardware store. Can anyone help me identify the threading type I am looking for? What are the dimensions I need to measure to confirm the identification?