Hardinge 5C Collet 1” with Internal Threads

[4thTool]

I’ve been looking on eBay for a Hardinge 5C Collet, 1”, with internal threads for a collet stop. That size comes up occasionally but I’ve never seen one advertised with internal threads. Which makes me wonder: does Hardinge even make 1”, 5C collets with internal threads?

 

[TeachMePlease]

This page listing all their 5c Collets 1" and larger that specifies "no thread" implies that no, they do not. https://shophardinge.com/productGrid.aspx?catID=6901

 

[TeachMePlease]

This page listing their 5c collets up to .999" and showing that up to .998" has the internal thread and .999" is spec'd as no thread says that no, they do not. Can you force a .998" collet open .002" to fit your 1.0" stock?

https://shophardinge.com/productGrid.aspx?catID=6896

 

[csteen]

Hardinge does make them as a 5C-SC meaning 5C stop collet that is threaded. It will not pass a 1" bar through though.

 

[sfriedberg]

Bore an internally threaded 5C emergency collet out to 1". The only way that won't work is if your part requires more than about 1.5" of contact depth (incredibly unlikely), or if the part will interfere with your drawbar bore. In the latter case, you couldn't use the asked-for collet anyway, even if you were given one.

 

[L Vanice]

Hardinge does make them as a 5C-SC meaning 5C stop collet that is threaded. It will not pass a 1" bar through though.

True, except SC stands for "step chuck." A hundred years ago, what we call collets were called "wire chucks." They were invented to hold wire of convenient length in watchmaker lathes, The idea soon was adopted to screw machines and larger precision bench lathes. Step chucks were like wire chucks, but had an internal step, usually caused by the "order hole" being larger than the hole inside the threads, or back end of the collet. Step chucks can only hold relatively short pieces.

The original Cataract No. 5 wire chucks had a maximum through hole of 1.00 inch. Later improvements in the steel strength allowed them to have order holes up to 1.0625 inch. I think it was in the 1930's that Hardinge started calling the Cataract No. 5 a 5C collet. They needed shorter names to stamp on the faces of the collets and were possibly the first collet maker to come up with a system of collet names using two or three characters stamped on the face of the collet.

Hardinge made a nice expanding stop assembly that works in 5C collets with no internal threads. The internal thread for a threaded stop assembly was not introduced until around 1970. Some makers of collets did not make their internal threads to the Hardinge standard, so Hardinge stops will not fit. And vice versa.

Anyway, the Hardinge collet catalog has separate sections for 5C collets and 5C step chucks, so you have to understand the difference when you are looking to buy a 5C collet with 1 inch or larger order hole.

Larry

 

[MrWhoopee]

Is it possible that an expanding collet stop (no threads required) would accomplish what you need?

TTC CBU-6 5C Collet Stop Set | 69-600-002 | Travers Tool Co., Inc.

 

[L Vanice]

Is it possible that an expanding collet stop (no threads required) would accomplish what you need?

TTC CBU-6 5C Collet Stop Set | 69-600-002 | Travers Tool Co., Inc.

Depends upon the part. As I mentioned, Hardinge made a nice stop for 5C collets without internal threads. It will do what the one at Travers will do, and they often are available on eBay.

The advantage of the stops for threaded collets is that they can accommodate longer parts. Hardinge has extension tubes in various lengths for stopping parts that extend outside the collet, back into the draw tube.

Larry

 

[Gordon Heaton]

Why exclusively Hardinge? I've got a couple of off brand inchers here with internal thread that will pass stock through. I'm sure you can find one if you can accept a different make.

 

[dieselpilot]

The Hardinge 5C collet I have is not threaded internally. I have a Lyndex 1" 5C with threads. Lyndex seem to be on size while open. Hardinge have a little spring when open. When bar or parts are over the collet nominal, things can get pretty tight. Stuff oring cord in the slots to help here.

I slightly bored the stop thread minor dia in the Lyndex to pull 1" aluminum bar, wasn't enough. The Hardgine 1" didn't help much. I had a Hardinge 25.5mm and that worked.

 

[FredC]

Why exclusively Hardinge? I've got a couple of off brand inchers here with internal thread that will pass stock through. I'm sure you can find one if you can accept a different make.

Well, you made me do it. I checked my 1 SC threaded collet with calipers and it says 1.002 to 1.004. The threads and ID just inside are black so that area was not ground or finished after heat treat. I assume it could be off center a few thousands due HT distortion. You get a bar that is a little out of round or has some micro dings and it will not feed.
Every shop I worked at had two 1 inch collets, one SC collet with threads for chucking against a stop and the plain collet for bar work and setting drilling tools on the chuckers or now my GT. Looks like I could use a long boring bar and barely skin the ID to make sure that the gauge bar is not being pushed off center by the not finished area.
Not going to do that as I already have the 2 purpose built 1 inchers and a skinned collet still might not work with minor dinged or out of round bars.

On the plain inch collet the cleared area through the back is 1.032".

I even have a threaded 1 hex 5C - SC collet (the hex only goes back .5 inches).

 

[4thTool]

Thank you one and all! I appreciate your help and the discussion.

 

[Janderso]

Why exclusively Hardinge? I've got a couple of off brand inchers here with internal thread that will pass stock through. I'm sure you can find one if you can accept a different make.

Thank you,
I have some Shars 5C collets that have less runout than a genuine (old) Hardinge.
I must have gotten lucky with some of these.

 

[Doozer]

Interesting.
I have some old ENCO collets in my miscellany collet collection.
They have maybe .0001" of runout. Truly amazing bit of workmanship
for a budget brand collet.

--Doozer

 

[Gordon Heaton]

With the old Enco, you never knew what would show up. I bought an unbranded 'made in USA' coaxial indicator and when it arrived it was a genuine Blake. Nice wood case and all. For about half the regular price!

 

[sfriedberg]

I miss Enco. Not everything they carried was that good, but they had some excellent deals. I used to buy most of my shop consumables from them.

 

[richard newman]

And they had great periodic sales

 

[lionelt]

Just checked all my 5C collets bought from Hardinge in Exeter, England and they all have internal threads for a stop. Have another no name brand that are used in an indexer and they are all internally threaded.

Edit. Listed as threaded internally.

5C Collets - Round - Imperial Sizes - Arc Euro Trade

https://www.mscdirect.com/product/details/79782512