ER25 v 5C Collets

[Adrian Parker 1Participant @adrianparker1]

EDIT JUMP DOWN TO NEW POSTS

Conventional wisdom appears to be that ER Collets are better than 5C collets because they are more versatile.

5C collets are for specific sizes only.

However can anyone advise me if there is any difference in accuracy or concentricity between the two collet systems?

Edited By JasonB on 17/02/2019 07:14:09

[Adrian Parker 1Participant @adrianparker1]

EDIT JUMP DOWN TO NEW POSTS

Conventional wisdom appears to be that ER Collets are better than 5C collets because they are more versatile.

5C collets are for specific sizes only.

However can anyone advise me if there is any difference in accuracy or concentricity between the two collet systems?

Edited By JasonB on 17/02/2019 07:14:09

[Adrian Parker 1Participant @adrianparker1]

[Chris TriceParticipant @christrice43267]

Technically ER should be better because both ends of the collet closes. This could make a difference on long pieces that protrude further out of the chuck.

[Chris TriceParticipant @christrice43267]

Technically ER should be better because both ends of the collet closes. This could make a difference on long pieces that protrude further out of the chuck.

[John McNamaraParticipant @johnmcnamara74883]

Hi Adrian.

5C collets are available for Hex and square bar also, not so in ER
Also it is easy to make a nose piece and draw bar for the lathe. If you do a lot of precision bar work on longer lengths.

As seen here:
**LINK**

However ER is a little more stable holding cutters straight due to the longer gripping length. normally you cannot pass long work through an ER collet.

If the budget is tight I would consider ER first.

Cheers
John

[John McNamaraParticipant @johnmcnamara74883]

Hi Adrian.

5C collets are available for Hex and square bar also, not so in ER
Also it is easy to make a nose piece and draw bar for the lathe. If you do a lot of precision bar work on longer lengths.

As seen here:
**LINK**

However ER is a little more stable holding cutters straight due to the longer gripping length. normally you cannot pass long work through an ER collet.

If the budget is tight I would consider ER first.

Cheers
John

[David LittlewoodParticipant @davidlittlewood51847]

John,

You can pass long work through an ER collet – provided the chuck is of the right type. The ones on a morse taper shank are (usually) solid, but the ones which screw on the spindle nose, or fit on a backplate, are (usually) capable of passing long work.

I have both types; the MT shank one is ideal for holding milling cutters in a milling machine, the others are ideal for use on a lathe.

I would certainly agree that the ER ones are more versatile (apart from the square/hex bit); I certainly use mine a lot more than the 5C ones.

David

Edited By David Littlewood on 08/05/2013 14:23:09

[David LittlewoodParticipant @davidlittlewood51847]

John,

You can pass long work through an ER collet – provided the chuck is of the right type. The ones on a morse taper shank are (usually) solid, but the ones which screw on the spindle nose, or fit on a backplate, are (usually) capable of passing long work.

I have both types; the MT shank one is ideal for holding milling cutters in a milling machine, the others are ideal for use on a lathe.

I would certainly agree that the ER ones are more versatile (apart from the square/hex bit); I certainly use mine a lot more than the 5C ones.

David

Edited By David Littlewood on 08/05/2013 14:23:09

[Anonymous]

I understood that ER collets were originally designed for hold tooling, whereas 5C collets were intended for work holding. Of course there's nothing to stop you holding what you like in any variety of collet.

In theory I suspect that ER collets can be bought that are better than 5C collets. A quick 'google' found ER collets with TIRs of 0.0002" or better, whereas the best I found for 5C collets was 0.0004". However, none of the suppliers operate in the ME market. For the ME user I expect that where the collets are purchased from will have a far greater impact on accuracy and concentricity than any theoretical accuracy standards.

Regards,

Andrew

Edited By Andrew Johnston on 08/05/2013 14:40:30

[Anonymous]

I understood that ER collets were originally designed for hold tooling, whereas 5C collets were intended for work holding. Of course there's nothing to stop you holding what you like in any variety of collet.

In theory I suspect that ER collets can be bought that are better than 5C collets. A quick 'google' found ER collets with TIRs of 0.0002" or better, whereas the best I found for 5C collets was 0.0004". However, none of the suppliers operate in the ME market. For the ME user I expect that where the collets are purchased from will have a far greater impact on accuracy and concentricity than any theoretical accuracy standards.

Regards,

Andrew

Edited By Andrew Johnston on 08/05/2013 14:40:30

[John McNamaraParticipant @johnmcnamara74883]

hi David

Yes…. I should have been more specific. and I use 5c in the lathe and a little indexer as well. ER on the mill.

Cheers

John

[John McNamaraParticipant @johnmcnamara74883]

hi David

Yes…. I should have been more specific. and I use 5c in the lathe and a little indexer as well. ER on the mill.

Cheers

John

[MICHAEL WILLIAMSParticipant @michaelwilliams41215]

There isn't much difference if considering just the collets in isolation .

The real difference in practical use comes from the means of mounting in machine spindle .

The 5C collet was designed to use directly inside the machine spindle – no intermediate arbours , no chucks , no overhang , very little accumulated error , minimal loss of headroom and excellent rigidity

The ER collet was designed to be used in a collet chuck mounted externally to the machine spindle – intermediate arbour , collet chuck , big overhang , lots of accumulated error , large loss of headroom and poor rigidity .

The tale of 5C collets not closing parallel is 90% myth – correct collet on correct size work closes perfectly . An error does arise with slightly undersize work but nothing usually to cause problems .

Many high class milling machines use in spindle collets to get the highest precision .

Not that common but machine spindles designed to use ER collets internally could be excellent for many purposes .

On larger machines with ISO or other big taper spindle mountings the advantages of quick tool changing can outweigh the disadvantages of external collets . In any case there is not so much loss of rigidity with big taper mountings .

Michael Williams

[MICHAEL WILLIAMSParticipant @michaelwilliams41215]

There isn't much difference if considering just the collets in isolation .

The real difference in practical use comes from the means of mounting in machine spindle .

The 5C collet was designed to use directly inside the machine spindle – no intermediate arbours , no chucks , no overhang , very little accumulated error , minimal loss of headroom and excellent rigidity

The ER collet was designed to be used in a collet chuck mounted externally to the machine spindle – intermediate arbour , collet chuck , big overhang , lots of accumulated error , large loss of headroom and poor rigidity .

The tale of 5C collets not closing parallel is 90% myth – correct collet on correct size work closes perfectly . An error does arise with slightly undersize work but nothing usually to cause problems .

Many high class milling machines use in spindle collets to get the highest precision .

Not that common but machine spindles designed to use ER collets internally could be excellent for many purposes .

On larger machines with ISO or other big taper spindle mountings the advantages of quick tool changing can outweigh the disadvantages of external collets . In any case there is not so much loss of rigidity with big taper mountings .

Michael Williams

[JoParticipant @jo]

I have never had any issues with using my 5C's they are excellent. The mounting of my 5C collet chuck has zero run out and I have Collets up to 1 1/4" (and28mm) in all the sizes that my drawings use. Whilst I have a ER32 holder I see no point in buying any collets to go with it as it is restricted to a much smaller maximum diameter than the 5C's.

I would recommend that you support long pieces of work which stick a long way out of any collet: It is not the inaccuracies of the collet that will be your problem but flex in the material as you machine it.

As for accuracy: The more you deviate from the standard collet size you will find that the collet is holding over less and less surface area as the bore of the collet is a specific size so effectively at the extreems it is holding on only three points, which is why it is possible to buy two standards of ER collets.

Cost wise I paid the same for a full 29 piece 32nd inch 5C's (up to 1" ) as you will pay for a 12 piece ER25 set (up to 5/8" ).

Jo

Edited By Jo on 08/05/2013 14:55:42

[JoParticipant @jo]

I have never had any issues with using my 5C's they are excellent. The mounting of my 5C collet chuck has zero run out and I have Collets up to 1 1/4" (and28mm) in all the sizes that my drawings use. Whilst I have a ER32 holder I see no point in buying any collets to go with it as it is restricted to a much smaller maximum diameter than the 5C's.

I would recommend that you support long pieces of work which stick a long way out of any collet: It is not the inaccuracies of the collet that will be your problem but flex in the material as you machine it.

As for accuracy: The more you deviate from the standard collet size you will find that the collet is holding over less and less surface area as the bore of the collet is a specific size so effectively at the extreems it is holding on only three points, which is why it is possible to buy two standards of ER collets.

Cost wise I paid the same for a full 29 piece 32nd inch 5C's (up to 1" ) as you will pay for a 12 piece ER25 set (up to 5/8" ).

Jo

Edited By Jo on 08/05/2013 14:55:42

[jason udallParticipant @jasonudall57142]

Add in the fact that 5C ( and 16C !) are available in "emergency" format to bore to required profile rhis allows a certain amount of flexabilty beyond ER

[jason udallParticipant @jasonudall57142]

Add in the fact that 5C ( and 16C !) are available in "emergency" format to bore to required profile rhis allows a certain amount of flexabilty beyond ER

[David LittlewoodParticipant @davidlittlewood51847]

Posted by MICHAEL WILLIAMS on 08/05/2013 14:50:27:

The 5C collet was designed to use directly inside the machine spindle – no intermediate arbours , no chucks , no overhang , very little accumulated error , minimal loss of headroom and excellent rigidity

This may be so – but how many of us have machines which can actually take a 5C collet in its spindle?

David

[David LittlewoodParticipant @davidlittlewood51847]

Posted by MICHAEL WILLIAMS on 08/05/2013 14:50:27:

The 5C collet was designed to use directly inside the machine spindle – no intermediate arbours , no chucks , no overhang , very little accumulated error , minimal loss of headroom and excellent rigidity

This may be so – but how many of us have machines which can actually take a 5C collet in its spindle?

David

[David LittlewoodParticipant @davidlittlewood51847]

Posted by MICHAEL WILLIAMS on 08/05/2013 14:50:27:

The 5C collet was designed to use directly inside the machine spindle – no intermediate arbours , no chucks , no overhang , very little accumulated error , minimal loss of headroom and excellent rigidity

This may be so – but how many of us have machines which can actually take a 5C collet in its spindle?

David

[Anonymous]

This may be so – but how many of us have machines which can actually take a 5C collet in its spindle?

David

You did ask; they're a bit small for both lathes and one of my mills, and too large for the other two mills. I use 5C collets on the 4th axis of the CNC mill.

Andrew

[Anonymous]

This may be so – but how many of us have machines which can actually take a 5C collet in its spindle?

David

You did ask; they're a bit small for both lathes and one of my mills, and too large for the other two mills. I use 5C collets on the 4th axis of the CNC mill.

Andrew

[Anonymous]

This may be so – but how many of us have machines which can actually take a 5C collet in its spindle?

David

You did ask; they're a bit small for both lathes and one of my mills, and too large for the other two mills. I use 5C collets on the 4th axis of the CNC mill.

Andrew

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