Umnum O-Rings Size and Sources

Tetsujin 140.6

Tetsujin 140.6

Gold Member
Joined
Jan 4, 2011
Messages
1,156
I'm looking for some replacement o-rings for my umnum.

I'm aware that CRK will ship replacements, and I know that another source is the local hardware store and the Danco #60 O-Rings (that measure 1/4 in. OD x 1/8 in. ID x 1/16 in. thickness), but I'm looking for other color options.

I've searched this forum and found the links to other sources to be dead.

Has anyone had recent success finding some in colors other than black?
Any links and assistance are appreciated.

Thanks.
 
Tetsujin 140.6 said:
Thanks. I posted a message for him on his profile page.
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Interestingly enough it seems like the only place to get colored o rings is from tattoo/body art places. I got mine at bodyartforms dot com. They have a whole bunch of colors. The 8 gauge o rings are the ones you want there. No issues with the fit or sizing.
 
Thin-Slice said:
Doubtfull since their only function is to soften the blow. Its the thumb studs that are doing the work of actually stopping.
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I was kind of thinking the same thing, but not going to call CRK about it either, thinking either maroon or blue o rings though
 
halden.doerge said:
Interestingly enough it seems like the only place to get colored o rings is from tattoo/body art places. I got mine at bodyartforms dot com. They have a whole bunch of colors. The 8 gauge o rings are the ones you want there. No issues with the fit or sizing.
Click to expand...

Thanks for the response and the link.

I just placed an order for a variety of colors, materials and hardnesses from an on-line O-Ring Store . . . not sure I'm allowed to post a link, but I will post which ones are the best when I receive them. Not surprisingly, they only cost pennies apiece, and despite ordering several lifetimes supply, the postage was the majority of the cost.
 
The dash size is 006 (from CRK). Any o-rings you can get in that size should work. I think the normal hardness is 70 (Shore A), but I could be wrong. McMaster has a number of o-ring options in that size.
 
Tetsujin 140.6 said:
Thanks for the response and the link.

I just placed an order for a variety of colors, materials and hardnesses from an on-line O-Ring Store . . . not sure I'm allowed to post a link, but I will post which ones are the best when I receive them. Not surprisingly, they only cost pennies apiece, and despite ordering several lifetimes supply, the postage was the majority of the cost.
Click to expand...

I'm interested to hear what you think about your experience with different materials and hardnesses. Please post back after you've played around with 'em. :thumbsup:
 
I've tried the silicon type commonly found at body art websites and noticed that they were softer than the stock o-rings. They work, but you hear the metal on metal click of the thumb stud to handle scale when the lockbar engages. You rarely see a durometer rating for these types. An actual o-ring supplier like some of the ones listed in this thread will provide the durometer and I've found that the 70a is pretty close, if not the same, to the stock o-rings. I would recommend going that route. Here's a pic with a complimentary photo bomb from one relaxed pooch.

image.jpg
 
I have the stock O rings and they make more of a sound then the plumbers size OO rings which are like a silent soldier.
 
I received the order from the O-Ring store.

First, the size (1/4 in. OD x 1/8 in. ID x 1/16 in. thickness) dash size 006 is a good fit. The durometer (hardness) rating of 70a makes for a very quiet closing knife. Quieter than the stock o-rings if that kind of thing is important to you.

Second, the colors do not look anything like what is depicted on your screen when you are placing your order. I ordered a number in orange, which are really more of a brown. The other colors are all much more muted than they appeared online. Just an FYI.

If I can ever figure out how to post pics again, I will post some up.
 
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