Cotter pin or cotter key?

Ultradog MN · May 28, 2016

Which term do you use?
To me they are pins as I think of a key as something to prevent a shaft from turning in a hub - woodruff, square, dutch, etc. But I know they both get used. Not an earth shattering deal.
Just wondering.

Jim Naden · May 28, 2016

(quoted from post at 02:10:16 05/28/16) Which term do you use?
To me they are pins as I think of a key as something to prevent a shaft from turning in a hub - woodruff, square, dutch, etc. But I know they both get used. Not an earth shattering deal.
Just wondering.

Technically speaking pin is the correct term but key is an accepted term.

Moonlite37 · May 28, 2016

On text I have only heard them referred to as pins, but in speech I have heard them referred to as keys. I am not sure but have heard them called "cotter"

James Howell · May 28, 2016

In several of the JD parts manuals they are referred to as [b:654c4848f0]<a href="https://en.wikipedia.org/wiki/Cotter_pin">cotter pins</a>[/b:654c4848f0].

Gary from Muleshoe · May 28, 2016

Potatoe / Potato

Ian Beale · May 28, 2016

http://www.thefreedictionary.com/cotter+key

Mostly split pins or rarely (almost never) cotter pins in this part of OZ

Leroy · May 28, 2016

Never heard tearm pin, always key as growing up, has changed over the years.

Geo-TH,In · May 28, 2016

From a uneducated self taught redneck prospective:

Keys are used on front wheel bearings, you bend two parts to keep nut in place,

There are three pins

perhaps more, I haven't had enough coffee to think clearly.)

A split pin or press pin.

Anther pin looks like a large version of a woman's Bobbie pin that you can install by pushing one part of it through a hole and the other side is bent to keep it in place. No bending, easily removed and reused.

Then there snap rings or clip that snaps in place on a grove in a shaft. These are the ones most likely to go flying when you remove them. Two versions inside and outside. Not sure if these are pins, clips, rings, tomatoes, tomotoes?

Not responsible for any of this information, lack of coffee is my excuse.

geo.

I have an assortment of all the things mentioned above in barn. Rural king or HF is where I got mine.

showcrop · May 28, 2016

I have never come across cotter key before. A key has always been the long narrow rectangular straight or moon shaped piece that you put in the keyways to keep the hub or pulley from turning on the shaft. Have you noticed how often a key is called a key way?

Alan K · May 28, 2016

Depends on if you are facing the direction of travel.

ed will · May 28, 2016

Hi, who cares? Ed Will Oliver BC wine capital

D beatty · May 28, 2016

Keys are used on shafts that are usually driven by power and sometimes see a roll pin used. Cotter pins are usually used as safety pins to keep nuts from backing off or spring cotter for things that get removed quit often.

Super-H-Mike · May 28, 2016

You rich guys can debate that, us poor folk have to use an old rusty nail !

Goose · May 28, 2016

Depends on whether they're SAE or Metric.

shaun wallace · May 28, 2016

Where did they come up with the name "cotter" or "woodruff". Was that the name of person that patented them or just of top of someones head?

sotxbill · May 28, 2016

Cotter pin may refer to:

In U.S. usage:

Split pin, a metal fastener with two tines that are bent during installation used to fasten metal together, like with a staple or rivet
Hairpin cotter pin, more commonly known as an "R-clip"
Bowtie cotter pin, a vibration-proof type of R-clip that is shaped like a bowtie
Circle cotter, a ring-shaped cotter pin

In British usage:

Cotter (pin), in mechanical engineering a pin or wedge passing through a hole to fix parts tightly together

This usage difference is often a cause of confusion when companies of both countries work together.

The original design for the cotter pin was designed by Dr. Rudolf Cotter in 1834. The original design employed a bolt with a hole drilled through and shank of metal placed within the hole.

Determined · May 28, 2016

To me the term key refers to indexing or aligning something.
To pin I think of a low or no load secondary retainer.

Doesn't matter what I think, but knowing what the store you are dealing with entered them into their computer as can be helpful.
How many times have you waited at a parts counter while somebody searches a computer trying to find a price for those shinny things you want to buy.

wisbaker · May 28, 2016

So if they're green they're PINS and if they're red they're KEYS?

1948CaseVAI · May 28, 2016

(quoted from post at 09:01:03 05/28/16)
I have never come across cotter key before. A key has always been the long narrow rectangular straight or moon shaped piece that you put in the keyways to keep the hub or pulley from turning on the shaft. Have you noticed how often a key is called a key way?

I always hear key way used to mean the slot where the key was inserted. Various machinist videos seem to use key way to mean the slot as well. Different parts of the country, I guess.

WGM · May 28, 2016

If John Deere refers to them as cotter pins then it must be so.

CenTex Farmall · May 28, 2016

Down here we say cotter pin although I recall reading cotter key in old textbooks I have.

Of course, we also refer to any carbonated drink as a "coke".

John M · May 28, 2016

Around here I hear a lot of people say "Carter" pin. Say it myself sometimes.

Spook · May 28, 2016

Cotter pins in my experience. Keys fin in a slot.

tractorguy2 · May 28, 2016

Dad calls them keys.

Ted in NE-OH · May 28, 2016

So who is Mr. Cotter? The inventor?

gab · May 28, 2016

When I was hanging out in the machine shed at about age four asking what's this and what's that it was cotter key.

Ozlander · May 28, 2016

This is a cotter key.
The one on my Montesa kick starter was fully round and tapered.

WellWorn · May 29, 2016

Hmmm. How about if Cotter goes through the end of a "pivot pin" to prevent it's lateral disengagement from a hole, it's a "pin". If the Cotter goes through a hole through both parts to prevent them from shifting rotationally (like a castle nut), it becomes a 'key', at least in some localities.

Pair-a-dice farm · May 29, 2016

In my neck of the woods it's a cotter pin but I have heard them referred to as a cotter key. I've always thought that a key was something that went into a machined slot. Either way, when I worked at the coop, if a customer called them a pin or key I knew what they wanted.

Jim Naden · May 29, 2016

(quoted from post at 08:40:42 05/28/16) Down here we say cotter pin although I recall reading cotter key in old textbooks I have.

[b:54cd794549][i:54cd794549]Of course, we also refer to any carbonated drink as a "coke".[/i:54cd794549][/b:54cd794549]

I have actually heard this, right here in Indiana where it is usually called either pop or sody pop...
Want a coke?
(opens refrigerator) We have Pepsi, Seven Up and root beer. Which would you like?

IA Roy · May 29, 2016

Just don't get that confused with a hairpin cotter which is something quite different

Rich'sToys · May 29, 2016

I grew up calling them cotter keys and still do most of the time.

I find it amusing that this thread is on its 3rd page!

Cotter pin or cotter key?

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