INFO) O-rings Specification

[Hoosier]

I did research about O-rings specification Please let me know if I headed the wrong way. I checked out the local hardware shops (they are using an odd number on O-rings). They mostly carry “Danco” brand that is Buna-N (=Nitrile) O-rings. It costs about 50 cent each. But, I have no information about Danco O-rings’ durometers.



I found out that the most common spare rings are 003, 010, 014, 112, and 214 (please see the attachment). Air-Oil.com offers a really good price except the high S/H charge. Their shipping charge is the same no matter how many I ordered O-rings I am not sure if it is worth to have that many O-rings as a spare though. But, it must be a better deal than just heading to LDS. The attachment shows $11.57 shipped for the mostly used O-rings’ combination.



Many experienced divers in this board argue that the higher durometer, 90, is much durable in H.P. DA Aquamaster and Dan Gibson also verified that SP uses EPDM materials.



Please let me know if there is something I missed.

 

[Jim Baldwin]

I did research about O-rings specification Please let me know if I headed the wrong way. I checked out the local hardware shops (they are using an odd number on O-rings). They mostly carry “Danco” brand that is Buna-N (=Nitrile) O-rings. It costs about 50 cent each. But, I have no information about Danco O-rings’ durometers.

I found out that the most common spare rings are 003, 010, 014, 112, and 214 (please see the attachment). Air-Oil.com offers a really good price except the high S/H charge. Their shipping charge is the same no matter how many I ordered O-rings I am not sure if it is worth to have that many O-rings as a spare though. But, it must be a better deal than just heading to LDS. The attachment shows $11.57 shipped for the mostly used O-rings’ combination.

Many experienced divers in this board argue that the higher durometer, 90, is much durable in H.P. DA Aquamaster and Dan Gibson also verified that SP uses EPDM materials. Please let me know if there is something I missed.

You might want to check and see if there is rubber and gasket store in your area. I buy my o-rings at Monroe Rubber and Gasket in Monroe, LA. All my tanks are DIN and of course take a slightly larger o-ring than standard yoke valves. I buy 50 to 100 at a time and always have few extras on all my dive equipment. I recently bought about 200 for my buddy who owns a dive shop in Cozumel.

They run about 15 to 20 cents a piece depending on size. This would save you quite a bit just on the shipping and handling.

 

[contengo]

I checked out the invoice. The total is less than $12. Gees... I think if I skipped a greasy burger on the way out I would save more money. How frugal are we?? I have found a better online deal, but I will refrain from announcing the savings. I don't want to seem like a cheapskate.

Anyway, the most durable material is polyurethane. Much better than danco stuff for sure. Danco sells mostly 70 durometer so it doesn't hold up to ozone, and pressure. Check out http://www.oringsusa.com/html/scuba.html for more sizes.

 

[oxyhacker]

Hardware store O-rings are sourced from many different suppliers, and quality is unreliable - I've had them oxidize and start cracking in as little as 6 months.

Air-Oil ones seem pretty good, but you don't really want to keep any O-rings around too long, nitrile especially, so don't buy too many. Best thing is to go in on a batch with some buddies and split them up.

I don't agree with those who say to routinely buy 90s. They should be used in certain applications where the reg manufacturer originally used them, but not indiscrimately on the "harder must be better" principle Nor is it a good idea to causually use different materials, like urethane. Different materials and hardnesses have different friction, sealing and wear characteristics which have an effect reg performance, and the reg manufacturer has spent a lot of time fine tuning their reg to work well. 95% of the time they end up using nitrile or EPDM.

BTW is is possible to ascertain the hardness and compound of an O-ring, by comparing it with other similar size rings of known hardness and compound. Hardness by simply putting them side by side and pushing down on them with a probe, compound with a little more difficulty by dropping them in a tall container of water side by side and comparing how quickly they sink since the different compounds have different