# R8 Collets



## EmilioG (Nov 10, 2017)

I buy R8 collets when I see them on sale, Hardinge, BP, Crawford and one or two Lyndex.
I only buy sizes that I need, no sets.  Hardinge is supposed to be one piece construction, no threaded inserts that are pinned or staked.
Can someone check their Hardinge and Crawford R8 collets and let me know if they have stake marks?
I suspect that there are some counterfeit collets being sold or rebadged as Hardinge, BP, etc...

My older Bridgeport collets are heavier and have no stake marks.  I will start checking the runout on some of these collets.


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## mksj (Nov 10, 2017)

I have both Crawford and Lyndex. They both have pressed in threaded bushings. Can't say on the Hardinge, but I do find the better quality R8 collets have some form of pressed in threaded drawbar section. The runout of my Lyndex and Crawford are under 0.0002", I had some Shar's metric R8 collets that were 3-4X worse and got replaced. Crawford is top of the heap in my experience, but no longer made if I recall. Bought mine from the UK. There is also an eBay seller who still has some sizes.
https://www.ebay.com/itm/R8-CRAWFOR...ARIOUS-SIZES-NEW-MOST-AVAILABLE-/121768291589
http://www.rotagriponline.com/index...tegory_id=818&option=com_virtuemart&Itemid=29

Mark
Lyndex top, Crawford bottom. 



Hardinge R8 collet.


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## EmilioG (Nov 10, 2017)

Thank you for the images.  I see that some Hardinge r8's have black oxide and some do not.
I have 3 Hardinge r8's that have stake/pinned marks on them.  Your's does not.   I'm trying to find out if Hardinge outsourced or changed the design or what. Maybe the Hardinge r8's are fake?  Only way to tell is to check the TIR with a tenth's DI.


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## Bob Korves (Nov 10, 2017)

EmilioG said:


> Only way to tell is to check the TIR with a tenth's DI.


Doesn't matter what brand they are if they perform!


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## Dan_S (Nov 10, 2017)

Three years a go I got a really nice 16ths set of Crawfords from http://www.usshoptools.com/. I chose Crawford because they actually listed what the gauge length for the TIR measurement was.


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## EmilioG (Nov 10, 2017)

By perform do you mean insert and spin?
It looks like I have one suspect r8 that is engraved Harding. Are Harding collets still made in Elmira NY?  I’m calling Harding on Monday.  I’ve never paid anything even close to $45 for a collet. I’ve bought them all for around $15 each.  Ill replace the one suspect r8 Harding, it’s a 1/2”


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## Bob Korves (Nov 10, 2017)

EmilioG said:


> By perform do you mean insert and spin?


By perform I mean that if they are within .0001", on axis, properly hardened, properly dimensioned, and fit beautifully, then I could not care less what name brand is stamped on them.  It is likely that even Hardinge has Monday morning and Friday afternoon work, and some of them slip out the door.  Some might also be counterfeit.  The only way to know is to test them -- just as you said, Emilio.  I agree!


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## Dan_S (Nov 10, 2017)

EmilioG said:


> I’ve never paid anything even close to $45 for a collet. I’ve bought them all for around $15 each.  Ill replace the one suspect r8 Harding, it’s a 1/2”



You aren't getting legitimate new Hardinge R8 collets for $15, unless someone didn't know what they had.

If you think $45 is bad, take a look at what they charge for Special Accuracy 5C collets.
https://www.shophardinge.com/product.aspx?partNo=10030018005000


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## EmilioG (Nov 10, 2017)

I've bought my legit Hardinge and Crawford collets on Ebay.  Most lightly used.
Who want's R8 collets with .008 TIR?   All import, or most import collets have terrible runout.
I only buy the sizes I need and use, not a whole set., and I prefer quality tool holders. I bought the Hardinge r8 3/4" to hold my Criterion
boring head. e.g.


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## Dabbler (Nov 11, 2017)

I just realized when reading your thread that I've never checked the runout of my spindle or my R8 collets.  Tomorrow I've got to check them!


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## EmilioG (Nov 11, 2017)

Let us what know you find Dabbler.  After doing more research on r8 collet quality, the one piece r8 collets are more precise, less run out, leading to longer tool life.
It appears that companies like Hardinge, Crawford, etc..had two lines of r8 collets and in regards to Crawford, their original run were machined from one piece of steel and as the company started to fold, they went with pressed in threads/staked, lower quality.  I can see this in my Crawfords.

My 3/4" Crawford is one piece with a ground end, no stake mark on the keyway.  Same with two of my Hardinge collets.  Hardinge started making their BP mills in Taiwan and could have a Taiwan r8 collet line as well.  Some later Crawfords tried to hide the pressed in threads but the stake marks give them away.  The best r8 collets have no marks on the keyway. One piece of steel.  If you don't care about the quality of your r8's, please disregard this thread.  I don't own many r8 collets but the 10 or so that I Use, I want to be of good quality.  Adding .0010 runout to the stack will make a difference in how long your end mills will last.


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## Dabbler (Nov 11, 2017)

Got some unexpected locksmithing to do today.  I'll get to the collets ASAP...


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## mksj (Nov 11, 2017)

I can't say if one piece is better than a two piece with pressed in thread. The threaded portion has no affect on the runout tolerance, more the collet body and clamping fingers machining.   I find the pressed in type collets to have nicer threads. All my (Asian) one piece R8 collets appear to have been cast and then machines, so far they have had the worse runout of all my collets. Another forum member did an extensive survey of the stated TIR, the manufacturer and where the R8 collets were made. After calling a number of collet manufactures it appears that most are now made in Asia these days. If you look at the listed maximum TIR for different brands, Lyndex and I believe Vertex is 0.0005" or better, I think Crawford states something like 0.0002" .  I use the Crawford collets to setup my edge finders and the tip alignment is within 0.0001" on rotation. Really do not care how it is made, or for that matter the name as long as it works, but of course those with better finish and machining, usually these are the more expensive of the bunch. Used ones can be hit or miss, rare that someone is selling NOS at a realistic price. 

I like the Crawford's, mine are very well made, but have gone up in price. If one is looking for a set without busting the bank, then I would go with a Vertex. In reality, the vast majority of end mills use standard sized shanks, so maybe 4 or 5 size collets will cover most everything (1/4, 3/8, 1/2, 3/4 and maybe 5/8). I also have both an ER32 system and a CNC chuck if I need to clamp some weird size. I rarely use my R8 collets, other than end mills larger than 1/2", otherwise I use my CNC chuck. An end mill lasts me a long time, I will break a tip long before it wears out. The TIR comes more into play for me when I am doing the DRO setup and defining the edges or centers with my edge finder.


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## EmilioG (Nov 12, 2017)

Do your Crawfords have pressed/staked threads? I have Crawfords with both pressed and machined from one piece.
I'll check the TIR on these collets one day just out of curiosity.  I like to use precision r8 collets for certain operations, like holding arbor shanks or
using carbide endmills., center finding, etc.. I buy the Hardinge r8's when they come up on Ebay, cheap. I just bought a 3/4" Hardinge r8 for $20 with the Hardinge tube, NOS, on a best offer deal. The seller wanted $45.00!  I just wait and buy the sizes that I need.  All I need is 5/16" to complete the set I use.


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## EmilioG (Nov 13, 2017)

I wrote to Harding and they told me that their $45 r8 collets have a tir of .0005”
They went on to say that they don’t usually make two piece collets, whatever that means, and that they have a special accuracy r8 for $87 each.  

My conclusion, thus far, is that not all collets, even from the manufacturers, are created equal. The only way to really know, is to check them yourself with a .0001” indicator. And, if your spindle, bearings, etc. are in good shape, you will have decent numbers.  

My belabored point is, at least know what you’re paying for. Looks like Crawford, Lyndex , etc downgraded specs also. The CNC world is making this all mute.  Old iron is on its way out.


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## Dan_S (Nov 13, 2017)

EmilioG said:


> I wrote to Harding and they told me that their $45 r8 collets have a tir of .0005”



Just as a side note, this number by itself doesn't mean anything. You need to know the TIR and the gauge length to know if a collet is good or not.


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## EmilioG (Nov 13, 2017)

That is true.  I'm sure this is a mean average at about 2". Who knows.  I'll just have to check my collets.


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## mksj (Nov 13, 2017)

EmilioG said:


> Do your Crawfords have pressed/staked threads? I have Crawfords with both pressed and machined from one piece.


My Crawford R8 collets are staked, as seen in the first picture. I purchased them earlier this year from Rotagrip so assume they are the remains of newer stock, if I recall they were under $15 each at the time. They appear very well made and beefy. The runout is usually specified as worse case,  they are much better then their guaranteed not to exceed specs. I use a Compac  (215GA) 0.0001 indicator with a 0.0004" per evolution dial, so a very sensitive indicator. There are many factors that affect the TIR, not just the collet.  What I am looking for is consistency when buying a number of collets (or a set), that the QA is such that you do not have some collets with a 0.001 or 0.002" runout like like the ones they replaced.


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## Dan_S (Nov 13, 2017)

EmilioG said:


> That is true.  I'm sure this is a mean average at about 2". Who knows.  I'll just have to check my collets.



Check page 35 of this PDF, its shows Crafords system.
http://www.rotagriponline.com/datasheets/5C.pdf

Basically the TIR and gauge length are related to the size of the collet.


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## EmilioG (Nov 13, 2017)

Thanks.  I just received my Ebay find, Hardinge high precision R8.  It's made like no other Hardinge I've ever seen.
Black oxided on the inside with two "lands". Tools slide in like silk. I got it for $20 on a best offer.  They didn't know what they had.
This is for my Criterion Boring head with 3/4" str. shank.  (The Compac DI is the best. Which model do you have 214GA?)

So, it seems that Hardinge and Crawford made various level quality r8's.  I have a Crawford r8 that is a one piece design, no stake mark on the keyway.  As long as an R8 can be made accurately with a pressed in thread, I don't mind.  See the last photos for Crawford R8's. Both are one piece but one has a nice ground finish.  See>>>  https://photos.app.goo.gl/7tavjP9yUfZWmMg83


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## cathead (Dec 30, 2017)

EmilioG said:


> I've bought my legit Hardinge and Crawford collets on Ebay.  Most lightly used.
> Who want's R8 collets with .008 TIR?   All import, or most import collets have terrible runout.
> I only buy the sizes I need and use, not a whole set., and I prefer quality tool holders. I bought the Hardinge r8 3/4" to hold my Criterion
> boring head. e.g.




For holding a boring head, I can't see where it would make any difference if the collet had run out or not.  A cheap import collet with
.008 run out would be capable of the same accuracy as a collet with minimal run out wouldn't it?


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## EmilioG (Dec 30, 2017)

E.g. The 3/4" r8 isn't only for my boring head. I use it to hold end mills and other tools.
Lyndex has a stated spec of .0011" TIR, Crawford UK supposedly, .0004", Hardinge .0007", so what kind of runout will a cheap $5 import r8 collet have?  A lot more than .001" I'm sure.


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## cathead (Dec 30, 2017)

EmilioG,

Sorry, I just couldn't resist making a comment.  I understand you like quality tools and that is a good thing.


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