Are all R8 collets the same?

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06-30-2006, 10:28 PM
SCCoupe

Are all R8 collets the same?

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!
06-30-2006, 11:28 PM
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
06-30-2006, 11:29 PM
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
06-30-2006, 11:36 PM
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
06-30-2006, 11:36 PM
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
07-01-2006, 01:20 AM
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...
07-01-2006, 02:10 AM
ZipSnipe

Good thread as I was kinda wondering the same....
07-01-2006, 02:43 AM
widgitmaster

I wonder if the USA is the only contry beinng inundated with inferior components from China!
Eric
07-01-2006, 04:21 AM
mxtras

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

Scott
07-01-2006, 04:34 AM
Geof

Quote:

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?
07-01-2006, 07:10 AM
mxtras

Yup. I agree.

Scott
07-01-2006, 12:41 PM
widgitmaster

Quote:

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!
07-01-2006, 12:44 PM
Redline

Very true!
07-01-2006, 01:48 PM
phantomcow2

They still cater to the buyer, looking for hte low cost.
I use import collets, some name "shards". They work, I've detected under .0005" of runout, I am happy. At work where we routinely hold a tenth, obviously these are not okay. But for the price, and what I do, I am pleased.
07-01-2006, 05:33 PM
Climatepro

I have a dovetail column bench mill that is a Rong-fu or one of the copies, and it came with a drawbar and a drill chuck that used a .368 major dia thread, but otherwise R-8 dimensions. I had to modify a Bridgeport drawbar to fit my length so I could toss that junk in the garbage, and use my other R-8 tooling.
02-01-2016, 10:55 PM
Doug4d3s

Re: Are all R8 collets the same?

Quote:

Originally Posted by SCCoupe

I have one of the Enco/Grizzly/Shop Fox mills that has the R8 collet taper. Are all R8 collets threaded the same? ...

The original post of this topic was made in 2006.

Recently (in 2016) I had this issue come up and the answer has changed, so I figured I'd add it on: nowadays, all R8 collets are not threaded the same.
A lot of the orient ones are threaded M12 x 1.75.
Most of the R8 collets sold in Europe and elsewhere are metric-bore, and threaded metric as well.
Some US retailers offer both; LittleMachineShop (for one example) offers mini-mill drawbars in both English and metric threading to allow using either kinds of collets. Much of what they sell ATM is China-made however.

I got into a situation where I have a Grizzly mill that has a 7/16"x20 thread drawbar, and I wanted a longer ER16 tool holder in order to use tiny mill bits better. I have a 1/8" R8 collet but they don't stick out of that very far.

Most of the cheaper Chinese-made ER collet chucks that have straight shanks have metric-sized shanks, if they don't have an MT shank. So I needed an R8 shank that could hold a 16mm tool....

When I went looking for R8 collets that were 16mm, most of them were titled something like "R8 x 16mm x M12",,,, which led me to investigate the thread issue further.

Metric-bore R8 collets sold by US-based companies will generally have the English thread.
If you buy metric-bore R8 collets from any of the China-direct shopping sites, today they're probably going to have the metric thread too. The few that do have the Imperial thread tend to specify so.

You could also just make another drawbar with the metric threading too, but some lazy people (like me) would rather just avoid the hassle and make sure all your tooling has the same threading.

-------

The 5C collets I don't know about... None I could find specified the threading they use. I don't use 5c's so this isn't an issue for me.
There is a Euro standard variation of 5c collets is called "K32" that normally does have a metric thread.
There has been some confusion over the K32 collets because some do come with the English threading, and they are similar enough overall to be able to fit in 5c collet holders--but the overall length and closing angle are different as well so it is not really "the same".
Mixing up 5c and k32 tooling will damage ,,,, something. They may appear to fit but really don't.

Buyer beware!........
06-18-2019, 09:25 PM
Uguessedit

I wanted to add here that not all r8 collets are the same. There is also a m12 metric version that requires a different drawbar. Careful on eBay they will often ship you metric when you order 7/16-20 and yes they won’t hold and a little too much arm will strip the threads even if you try and chase a 7/16-20 down. Pretty much all the china arbors we purchased had to have helicoils installed. It was still less than buying an expensive arbor but it’s a pain to have to repair a new product.

Quote:

Originally Posted by Doug4d3s

The original post of this topic was made in 2006.

Recently (in 2016) I had this issue come up and the answer has changed, so I figured I'd add it on: nowadays, all R8 collets are not threaded the same.
A lot of the orient ones are threaded M12 x 1.75.
Most of the R8 collets sold in Europe and elsewhere are metric-bore, and threaded metric as well.
Some US retailers offer both; LittleMachineShop (for one example) offers mini-mill drawbars in both English and metric threading to allow using either kinds of collets. Much of what they sell ATM is China-made however.

I got into a situation where I have a Grizzly mill that has a 7/16"x20 thread drawbar, and I wanted a longer ER16 tool holder in order to use tiny mill bits better. I have a 1/8" R8 collet but they don't stick out of that very far.

Most of the cheaper Chinese-made ER collet chucks that have straight shanks have metric-sized shanks, if they don't have an MT shank. So I needed an R8 shank that could hold a 16mm tool....

When I went looking for R8 collets that were 16mm, most of them were titled something like "R8 x 16mm x M12",,,, which led me to investigate the thread issue further.

Metric-bore R8 collets sold by US-based companies will generally have the English thread.
If you buy metric-bore R8 collets from any of the China-direct shopping sites, today they're probably going to have the metric thread too. The few that do have the Imperial thread tend to specify so.

You could also just make another drawbar with the metric threading too, but some lazy people (like me) would rather just avoid the hassle and make sure all your tooling has the same threading.

-------

The 5C collets I don't know about... None I could find specified the threading they use. I don't use 5c's so this isn't an issue for me.
There is a Euro standard variation of 5c collets is called "K32" that normally does have a metric thread.
There has been some confusion over the K32 collets because some do come with the English threading, and they are similar enough overall to be able to fit in 5c collet holders--but the overall length and closing angle are different as well so it is not really "the same".
Mixing up 5c and k32 tooling will damage ,,,, something. They may appear to fit but really don't.

Buyer beware!........

- - - Updated - - -

Quote:

Originally Posted by 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

Because they ship the m12 arbors bait and switch. We never had luck with tapping it always requires a drill and helicoil.