O-ring kit, which one?

Dunbar

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I need to re-stock on O-rings and looking at Amazon I see several kits under $20 with various numbers of O-rings some SAE some metric and combos.

For my diesel truck I get low sulfur tolerant ones from DieselOrings.com But I want a kit for automotive and general shop use. Other uses are pool equipment, reverse osmosis, gasoline power tools etc etc.

What should I look for in a kit?
 

e9999

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I do remember watching a video by a diesel tech who was saying that he makes all his Orings himself with a little glue-on kit, and -surprise to me- that he never had one fail before... But that may be a better solution mostly if you are working a lot with odd size Orings or with weird fluids, perhaps. Cuz you still have to stock various thicknesses.
 

pb4ugo

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I picked up a cheap kit at harbor freight yrs ago for general uses. If I need specific critical application seal, I'll get a seal from that manufacturer. A Volvo outdrive gets Volvo seals.
 

Dunbar

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That makes sense. I was at HF and picked up a metric kit.
 

e9999

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yes, one problem with cheap "universal" kits is that you often don't know for sure what the material is. Either they don't say or you may not trust it. And if it's not compatible... well, leaks ensue... You can be sure that engineers working on important equipment won't be using a universal kit from HF. Having said that, for DIY jobs around the shop, well, if you don't mind going back into the gizmo again after a while, and if no serious damage can occur, why not? But on a truck that goes off the beaten path, I would not.
 

scrapdaddy

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Did you look at Grainger's....https://www.grainger.com/category/hardware/o-rings-and-o-ring-kits/o-ring-kits
 

NMC_EXP

 
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If you can find a kit from Parker Hannifin O-ring Division buy that one. Parker is an excellent supplier and they know how to make good o-rings.

I had corporate design control for o-rings for a big company and Parker was our supplier.

Problem with O-rings is without specialized equipment: (1) You cannot tell by looking if the material is Viton, nitrile, neoprene, EPDM or AOC (Any Old Crap) rubber. (2) You cannot accurately determine the durometer hardness with your thumbnail. (3) You cannot accurately measure the inside and cross section diameters.

Only way to be sure is to buy from a known reliable supplier.

If Parker does not sell kits as mentioned McMaster Carr or Grainger might be a good option.
 

Dunbar

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Thank you Raton! Thats the kind of info I was seeking. I'd like to have a general kit on hand. Some of the things I would need them for will have service manuals or internet info with the correct type and size. Other items I might have no clue and just size it up. With prices from less than five bucks to twenty times that amount I figured there had to be a quality scale. I already picked up a metric kit labeled nitrile but if I find myself without the proper item or if these start failing, I'll come back to this post and go shopping.
 

NMC_EXP

 
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You can trust Parker.

For a long lasting seal you must select the correct type of rubber and there are many types. These fall into two broad categories: (1) oil & fuel resistant, and (2) non-oil resistant.

These two categories are further subdivided by parameters such as max and min operating temperature and resistance to specific types of fluids such as gasohol and biodiesel.

Nitrile (aka Buna N) is a good low cost oil resistant material and is the first successful synthetic rubber. Compared to high performance rubber types It has a relatively low upper temp limit.

If you know the specified correct size for an application you are ahead of the game. O-ring size is important because seal joint design is typically based on about 20% compression of the o-ring cross section and that is not very much in inches or millimeters. O-ring too small and the sealing force will be low. Too large and its 10 lb of stuff in a 5 lb bag and since rubber is an incompressible solid the rubber may split. Either way you have a leak.

Be glad to help if you have general questions.
 
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