How do I cut o-ring grooves

Of all the thousands of o-ring grooves I have cut . I have always cut them with straight sides and flat bottoms . The blueprints called straight sides or up to 5 degrees taper . Larger at the top. I have special depth mic rods to check the width and location of the grooves. I also have special gages to check dia of the Id grooves. And I mostly used hand ground old school tools. I remember hating to grind the tools in my 20s . But that was over 60 years ago and you could not buy all the store bought tools like today.
jimsehr
 
Take a look at ThinBIT by Kaiser. They have inserts ground for the correct O-ring profile. Not cheap (maybe $120 for the tool and the inserts), but a purpose made insert is the *right* way to do it.

These are certainly not the only inserts that do the job, but I've been very impressed with the Groove-N-Turn product line.

Groove-N-Turn Page 7-8 shows a nice boring bar and page 1-12 shows the inserts for the O-Ring.

 
I rebuilt hydraulic cylinders for 15 years in the past. All had straight sides and flat bottom. Inserts do have a corner radius witch depends on the with. the smaller the with the smaller the radius, the larger the width the larger the radius. The radius serves to purposes, 1 for preventing the part from cracking and also aids in too chipping. That is for cylinders and rods or pistons.
 
There are whole books on cutting o ring glands, static, rotary and reciprocating. I have seen tapered sides and straight sides, radiused bottoms and square bottoms. A lot depends on the application and that is what is called engineering.
 
Thanks for all of the great answers. You've given just the info and required reading to set me on my way. I can't thank you fellas enough. Learning is fun and this is a great place to learn from the "real life experience" crowd. Thx again.
 
Jimsehr said:
Of all the thousands of o-ring grooves I have cut . I have always cut them with straight sides and flat bottoms . The blueprints called straight sides or up to 5 degrees taper . Larger at the top.
jimsehr
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I, also have been cutting o-ring grooves for the last 40 years and agree 100% with Jimsehr. Most times the corner radii have been .005 to .010 maximum. All of the Googling in the world will not give you “experience”.
 
Geez, this is getting complicated. Just grind a high speed tool to match the groove that's already there. Duplicate the the existing groove.
 
epanzella said:
Geez, this is getting complicated. Just grind a high speed tool to match the groove that's already there. Duplicate the the existing groove.
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This thread has (re)taught me how expensive being a carbide shop is! $125 for an insert that I'll probably overfeed and destroy the first time I use it, then only use for 1 hole is crazy. I'll stick to grinding and burning HSS thank you very much!
 
ErichKeane said:
This thread has (re)taught me how expensive being a carbide shop is! $125 for an insert that I'll probably overfeed and destroy the first time I use it, then only use for 1 hole is crazy. I'll stick to grinding and burning HSS thank you very much!
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I've got a drawer full of various HSS tools both ground by me and inherited. There are so many different sizes of O-ring grooves that more often than not I have to grind one because none of the half dozen or so groove cutters I've already ground are the right size. I can't imagine buying a new carbide tool every time every time I needed to set an O-ring. Even if I didn't mind spending the money (which I do) the wait for shipping in the middle of a project would annoy the crap out of me. (and I can't find toilet paper)
 
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