5c collet holding capacity

[JouniPParticipant @jounip]

Hello

 

ER collet can hold bar +0 mm – (-1 mm) nominal capacity as far I know. What I do not know is holding capacity of 5c collet. Can someone tell me that.

 

JP

[JouniPParticipant @jounip]

[JasonBModerator @jasonb]

They should really only be used to hold their nominal size, for example a 10mm 5C should only be used to hold 10mm work not say 9.0mm or even 9.5mm work. In reality you can allow a small tollerance say 0.1mm as often bar is a little undersize.

 

The reason is that ER collets are slotted at both ends so when compressed they grip along their whole length. 5C collets are only slotted at one end so if overtignhtened only the front end will be gripping the work.

 

JAson

Edited By JasonB on 03/07/2011 15:39:13

[JouniPParticipant @jounip]

That is what I have heard about, only be used to hold nominal size and ER collets are better in this way. But there is always some tolerance. So, if I have say a 19.0 mm, 19.5 mm and 20 mm 5C collets, is there gap between 19 – 20 mm they can not hold without losing consentricity or do I ruin my collet if I use 20 mm collet on 19.6 mm bar?

 

How about if I have just 19 mm and 20 mm collets,? Gap or ruin between 19 -20 mm?

 

 

Or 3 mm, 3.5 mm and 4 mm collets? Gap or ruin between 3-4 mm?

 

JP

[JasonBModerator @jasonb]

As I said you really don’t want to go more than 0.1mm below nominal size so

 

20mm will hold 19.9 – 20.0

19mm will hold 18.9 – 19.0

3mm will hold 2.9 – 3.0

 

If there are specific sizes that you need to hold then buy the emergency collets and bore to suit.

 

J

[John Stevenson 1Participant @johnstevenson1]

Or buy one of these.

 

5C to ER32 so no gaps from 0.5mm up to 20mm and the equivalent in imperial.

 

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[JouniPParticipant @jounip]

Thank You

 

Holding tolerance for 5C collets seems to be quite small and 5C to ER32 collet chuck sound a good advice.

 

JP

 

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