What would you pay for convenience?
Someone on ECF went to the trouble of figuring out the sizes for Kayfun rings and posted links for McM. Likewise for screws. I stocked up on them. But they came in packs of either 25 or 50. I didn't mind because I mostly use KFL's and I have quite a few of them.
On the other hand I have some Lemo tanks and nobody ever found an exact match for the tank seal rings. They are flat washer style rings. I've gone through threads here where people tried multiple different sizes from different sources. Some were found that aren't exactly right but sort of work. You can send them a ring and they will make them for you, but you have to buy large quantities, 200 I think, and pay quite a lot. If someone was still selling Lemo rings I would pay a premium for them, but I left it too late.
It isn't easy to figure out the exact size of a soft rubber ring when fractions of a millimeter matter, especially for non-standard or complex profiles. For a lot of people it would make sense to pay a few extra bucks for a pack of rings rather than try to figure out the sizes, hope you got it right, and buy bags of 50 of 4 different sized rings.
Someone on ECF went to the trouble of figuring out the sizes for Kayfun rings and posted links for McM. Likewise for screws. I stocked up on them. But they came in packs of either 25 or 50. I didn't mind because I mostly use KFL's and I have quite a few of them.
On the other hand I have some Lemo tanks and nobody ever found an exact match for the tank seal rings. They are flat washer style rings. I've gone through threads here where people tried multiple different sizes from different sources. Some were found that aren't exactly right but sort of work. You can send them a ring and they will make them for you, but you have to buy large quantities, 200 I think, and pay quite a lot. If someone was still selling Lemo rings I would pay a premium for them, but I left it too late.
It isn't easy to figure out the exact size of a soft rubber ring when fractions of a millimeter matter, especially for non-standard or complex profiles. For a lot of people it would make sense to pay a few extra bucks for a pack of rings rather than try to figure out the sizes, hope you got it right, and buy bags of 50 of 4 different sized rings.