Are all R8 collets the same?

[SCCoupe]

I have one of the Enco/Grizzly/Shop Fox mills that has the R8 collet taper. Are all R8 collets threaded the same? I see some on ebay with standard threads to hold the collet in, but the mill being from China, maybe im dealing with a metric thread or is there a standard for this sort of thing. Also, im trying to fin the collets that have the allen bolt that holds the bit in. I understand that this type is better? Is there a certain name for that type of collet to make searching easier?

Thanks all!

[mxtras]

7/16"-20 UNF is the thread, and to my knowledge - yes - all R-8 collets are the same.

Well...you know what I mean - they are meant to be the same. The quality of some off brands could always be called into question.

The holder you refer to is called a Weldon style tool holder. Is it better? I don't think so. For one reason, the tool has to have a flat on it to be used and not all end mills are available with a flat. Sure you can grind one on yourself but it can be a pain on a large diameter, solid carbide end mill. Additionally, the set screw requires the holder to be longer therefore increasing the space consumed for tooling. This may not be an issue for you depending on the kinds of parts you are running. However, the added length reduces the overall rigidity of the tool and increases the abuse potential to the spindle bearings during side milling.

In my opinion, you can't get any more rigid than an end mill in a collet - not in the world of R-8 machines anyway.

Scott

[widgitmaster]

YES!
All R8 collets have a 7/16-20 thread, that is what makes them "R8 Industry Standard"
My Bridgeport mill is a clone from China, and it uses standard R8 collets!

The same holds trut for 5C collets!

However, some of the cheezy Chinese machine parts and accessories may not have a perfect thread to accept the world standards, I have had that happen to me on a 5C Collet Closer for my new lathe! The thread in the draw-bar was not made right, and none othe collets would screw in to it!

Eric

[acondit]

They are called "R-8 end mill holders" and have the set screw to hold in the end mills. They are available through Enco, Grizzly and HarborFreight, plus many others.

I would expect them to all have a standard thread (but I don't know for sure). Maybe the reason they aren't so popular in Europe is because they have an "Imperial" thread???

Alan

[mxtras]

I have a few 'Asian born' collets that I had to run a tap through to engage the draw bar but other than that, they are not all that bad.

Scott

[NC Cams]

The cheap import collets are SIZED as R8 but they vary in quality and subsequently FIT.

For run of the mill work, the import stuff is fine. However, for more precise work, go with a more premium grade - we use Lyndex (affordable and GOOD with no appreciable runout). Bridgeport/Harding makes real, REAL good ones and the price reflects it but surprisingly, they're not THAT much more.

For the Grizzly/Emco line of mills, the import stuff is fine to get you going. When you can SEE the difference that a few tenths runout does to sizing/fit/finish, you'll automatically know when to upgrade to Lyndex or better grade collets...

[ZipSnipe]

Good thread as I was kinda wondering the same....

[widgitmaster]

I wonder if the USA is the only contry beinng inundated with inferior components from China!
Eric

[mxtras]

Naw - I am sure China has been putting up with it longer than we have!

Scott

[Geof]

Originally Posted by widgitmaster I wonder if the USA is the only contry beinng inundated with inferior components from China! Eric

Mostly imported by US companies and bought by US customers looking for the lowest price. So who is to blame?

[mxtras]

Yup. I agree.

Scott

[widgitmaster]

Originally Posted by Geof Mostly imported by US companies and bought by US customers looking for the lowest price. So who is to blame?

Yea, but I bet most of those American company owners have Green Cards!