Metric O-Ring kit

[Foster143]

I currently own a SAE O-ring kit which never seems to fit anything I need it for. It's one of those red case cheapies you can pick up almost anywhere. What I never realized up until recently was O-rings come in metric sizes also. Most everything I work on is metric so I'm hoping that's why my SAE kit never has the one I need. I can pop on Amazon and there are Metric kits available which are priced cheap and that concerns me as far as quality and size. I wonder if they are they same **** that's in my SAE kit just converted to Metric sizes.

I see Grainger offers several but they run from inexpensive to over $170.00 leaving me scratching my head still. Any suggestions or advice appreciated on a quality Metric kit affordable for home use.

 

[bwringer]

McMaster-Carr has some reasonably priced metric kits. Which one to get depends somewhat on your applications.

I work primarily on metric motorcycles, so something like this with a nice assortment of the smaller sizes might do nicely for not much money:
https://www.mcmaster.com/9443K36/

Still, I've ended up buying quite a few oddball or larger sizes when needed. McMaster stuff gets to me overnight, so it's not too painful.

 

[BlakeTheCarGuy]

For O-Rings Harbor Freight is fine I use them all the time


Sent from my iPhone using Garage Journal

 

[Foster143]

McMaster-Carr has some reasonably priced metric kits. Which one to get depends somewhat on your applications.

I work primarily on metric motorcycles, so something like this with a nice assortment of the smaller sizes might do nicely for not much money:

Still, I've ended up buying quite a few oddball or larger sizes when needed. McMaster stuff gets to me overnight, so it's not too painful.

Thanks for the link. That looks just like the kit I was looking at at Grainger but about half the price. I have a small powersports repair shop and I mainly work on ATV's which are all metric.

 

[jayemm]

About 5 or 6 years ago I bought both SAE and Metric O-ring kits from Harbor Freight in the red and blue cases.They were not SAE resized to metric dimensions.The metric tended to be thinner in cross section compared to SAE of the same O.D. or the SAE were fatter which ever way you want to look at it.They were made in Thailand IIRC.Since made in China if it makes any difference.These are the nitrile(buna-N) o-rings commonly used in many places.
And what did I find out? Well after replacing seals in two floor jacks which were metric,I found out that the kit had 1 (maybe 2) of the seals that I needed. Hence a trip to the hardware store and wherever else I forget.

My take on it ----is to order/acquire correct seals for a job from either measuring after teardown or parts diagram rather than rely on the kits having the sizes you will need.They are cheap enough to have on hand to maybe work in a pinch especially if you live in the boonies,but in my very limited need for o-rings it seems the kits never had the right size.

 

[DHCrocks]

https://www.amazon.com/gp/product/B07DN6Z7T7/?tag=atomicindus08-20

I got this set from Amazon...to have on hand incase something comes up. seems like good quality, they are uniformly shaped and the case neatly keeps them organized. Comparing the SAE and the metric, the sizes look identical but I guess if you have really tight tolerances then it might make a difference. One thing I did notice was that the diameter of the o-ring cross section was slightly different between the sets.

 

[Jlarson]

I get a lot of mine from our hydraulic hose place. Most hose places are gonna have various O ring kits.

 

[Danglerb]

Lesson one on Orings, there are literally thousands of different sizes and types. About a dozen materials, round and square cross section, and maybe 4 or 5 thicknesses in at least 50 sizes.

I would start with a couple fairly cheap sets, then job by job keep the remains of the box of 20 or 50 you order from Mcmaster Carr.

When in doubt, order the replacement part from the manufacturer of the device, as the old one may have shrank or expanded over time, so measuring doesn't work.

 

[measuredtwice]

I've bought o-rings from several sources and there can be a BIG difference in the quality. The cheap stuff I've bought direct from China doesn't even seem to be made of the same material as the stuff that I've bought from reputable sources. (comparing silicone to "silicone" or buna 70 to "buna 70")

I've had good luck with Grainger and McMaster. But for small quantities for home use, I've previously found that O-Rings and More was the least expensive source of QUALITY o-rings since they have free shipping with purchases over $15.

https://www.oringsandmore.com/

 

[M6erfan]

I've bought o-rings from several sources and there can be a BIG difference in the quality. The cheap stuff I've bought direct from China doesn't even seem to be made of the same material as the stuff that I've bought from reputable sources. (comparing silicone to "silicone" or buna 70 to "buna 70")

I've had good luck with Grainger and McMaster. But for small quantities for home use, I've previously found that O-Rings and More was the least expensive source of QUALITY o-rings since they have free shipping with purchases over $15.

https://www.oringsandmore.com/

I second everything about this post ^. I've used oringsandmore too, high quality.

 

[bwringer]

Thanks for the o-rings and more link! Hadn't heard of them.


- I'll confess that I've used the o-rings from the metric sets at Harbor Freight several times with zero problems. They have I think at least four different sets in different ranges and materials, and I have them all.

- Having some metric o-rings on hand has saved me a trip or a wait many, many times. They're definitely worth having around. But I'd say many more times, I don't quite have the correct size on hand, and I have to order OEM or from McMaster-Carr. Always something of a crapshoot, but even if it only works out once in a while, you're quickly ahead of the game in time and money.

- A few motorcycle/powersports parts diagrams actually list the o-ring sizes; it's worth looking anyway.

- Pay attention to the fluid and the heat range. In some high heat applications, you have to use Viton o-rings since the usual Buna-N will crumble quickly. Buna-N works great for oil, gas, and antifreeze, but not brake fluid or A/C sytems.

- It might also be worth having some metric o-ring cord stock and a splicing kit on hand.

 

[Foster143]

About 5 or 6 years ago I bought both SAE and Metric O-ring kits from Harbor Freight in the red and blue cases.They were not SAE resized to metric dimensions.The metric tended to be thinner in cross section compared to SAE of the same O.D. or the SAE were fatter which ever way you want to look at it.They were made in Thailand IIRC.Since made in China if it makes any difference.These are the nitrile(buna-N) o-rings commonly used in many places.
And what did I find out? Well after replacing seals in two floor jacks which were metric,I found out that the kit had 1 (maybe 2) of the seals that I needed. Hence a trip to the hardware store and wherever else I forget.

My take on it ----is to order/acquire correct seals for a job from either measuring after teardown or parts diagram rather than rely on the kits having the sizes you will need.They are cheap enough to have on hand to maybe work in a pinch especially if you live in the boonies,but in my very limited need for o-rings it seems the kits never had the right size.

That's been the main issue with my SAE kit, they all seem to be to wide/fat for any application I need them for. Thanks for the reply

 

[Foster143]

Thanks for all the info and replies and links. Never would I have thought I would post about O-rings. LOL. I'm pretty sure these basic kits will never have what I need when I need it but wishful thinking makes me want to have them on hand anyway. I'll probably snag a cheap metric kit just in case and move on to the next of 50 issues on the to do list.

 

[rlitman]

That's been the main issue with my SAE kit, they all seem to be to wide/fat for any application I need them for. Thanks for the reply

In the few dozen or so o-rings I've replaced from my kits, ONE has been metric and the rest have come from my SAE kit. My metric kit still paid for itself, but it sounds to me like your applications are far more "metric" than mine.

 

[jjkrjh]

Even with metric o-ring kits we were running into o-rings that still weren't right. As a fluke we tried getting a JIS o-ring kit. Between the Sae, Metric, and JIS kits haven't had many issues other than very large o-rings. The JIS is actually used more than the metric for seals between machined parts.