Turning Rubber Round Stock ?????

[JoeLee]

I need to make some rubber washers. They need to be fairly firm but still seal under the head of a screw. I'm wondering if neoprene of 75 shore A durometer can be turned and drilled?? or is it too soft.
This material is the best choice for being in contact with oil. I can't have anything that is too soft or it will squeeze out when the screw is tightened down.

JL..............

[1-800miner]

Buy some hose and slice it?

[boslab]

Stuff it in the freezer first
Mark

[bob308]

that's how we did it freeze it then machine it. some times it has to be frozen again to finish

[hermetic]

+I have made rubber washers on the lathe before by simply slipping a piece of rubber tube over a suitable size piece of round bar and cutting with a stanley knife with the lathe revolving at fairly high speed, works like a dream!
Phil

[garyhlucas]

Buna-N otherwise called nitrile is usually the go to elastomer for oil. Rubbers are usually machined by grinding. It is surprising the nice finish you get that way. Not good for drilling but you can slice off pieces with a narrow grinding wheel and leave a nice finish.

[CalM]

Many good comments already...

I need to make some rubber washers. They need to be fairly firm but still seal under the head of a screw. I'm wondering if neoprene of 75 shore A durometer can be turned and drilled?? or is it too soft.
This material is the best choice for being in contact with oil. I can't have anything that is too soft or it will squeeze out when the screw is tightened down.

JL..............

But if you want to seal under a fastener, you MUST capture the rubber part.

My favorite is an O-ring with a washer that has a hole large enough to contain the o-ring, but snall enough to stay completely under the fastener head.
These can be purchased.

A "cleaner" job is with an o-ring groove cut into the underside of the fastener head.

[lost_cause]

slight hijack, but this is of interest to me too...

one of my cars has a fiberglass body, and in some places it uses expanding rubber bushings to attach the fiberglass body to the steel chassis. there is a pocket made into the fiberglass and the rubber bushing locks into it by tightening a bolt into a brass nut inside the rubber bushing. the bushings on my car have deformed and hardened with age to about the consistency of delrin and i've been trying to figure out how to make new ones and the idea of freezing the rubber and then machining it never occurred to me. i'll see if i can salvage one of them toget measurements from and give it a try.

[the kid]

I've had good luck in the past using rotary files, I. My instance I needed to drill some holes in some rubber stoppers, I used a dremel tool to do it and I got some very nice clean holes and the stoppers were not very hard rubber at all, I don't know the type, they were from ace hardware. freezing is a neat idea I've never considered, will have to try that if the situation should arise again.

Oh higher speed the better in my experience.

[Guido]

http://www.mcmaster.com/#standard-washers/=v4imbn

[CalM]

slight hijack, but this is of interest to me too...

one of my cars has a fiberglass body, and in some places it uses expanding rubber bushings to attach the fiberglass body to the steel chassis. there is a pocket made into the fiberglass and the rubber bushing locks into it by tightening a bolt into a brass nut inside the rubber bushing. the bushings on my car have deformed and hardened with age to about the consistency of delrin and i've been trying to figure out how to make new ones and the idea of freezing the rubber and then machining it never occurred to me. i'll see if i can salvage one of them toget measurements from and give it a try.

Look up "Well Nuts" ;-)

[lost_cause]

Look up "Well Nuts" ;-)

huh... just when i think i can't know any less, i amaze even myself. i've probably seen some of these in different sizes and lengths than what i need, but i never put two and two together and realized that what i need for this car may be an off the shelf item. i guess i should have known because some of these older european vehicles use a pretty fair amount of off the shelf parts. if i can figure out what the original size is maybe i can fix that flapping fender.

[JoeLee]

But if you want to seal under a fastener, you MUST capture the rubber part.

My favorite is an O-ring with a washer that has a hole large enough to contain the o-ring, but snall enough to stay completely under the fastener head.
These can be purchased.

A "cleaner" job is with an o-ring groove cut into the underside of the fastener head.

The O-rings might just be the way to go. These have to go under the head of a #6 and #8 pan head screw. Cutting a groove on the underside of the head would be a challenge, just the set up alone would be, but a thin O-ring would do the job just fine providing they don't blurp out when the screw it tightened. That's why I chose the harder durometer neoprene.
I guess I'll have to experiment a little.
I did check McMaster and that is where I found the neoprene rod.

JL................

[EddyCurr]

Would O-Ring Boss (ORB) fittings or something HSM'd
that resembles them meet the needs of your application,
JL ?

Edit: disregard - irrelevant to the OP's intended application

.

[CalM]

#6 or #8? Use fiber! not rubber

The O-rings might just be the way to go. These have to go under the head of a #6 and #8 pan head screw. Cutting a groove on the underside of the head would be a challenge, just the set up alone would be, but a thin O-ring would do the job just fine providing they don't blurp out when the screw it tightened. That's why I chose the harder durometer neoprene.
I guess I'll have to experiment a little.
I did check McMaster and that is where I found the neoprene rod.

JL................

Gasket sheet material will be ideal!

A snug fit on the screw shank, OD doesn't matter.

I punch those out of sheet material with arch and flat punches into end grain soft wood!