[MFchief]

Hi All,

Tormach has started offering Serrated 5C collets in their store. Anyone have any experience with these? Would it be a good or bad idea for the TTS collet?
I believe the idea is to reduce slipping, but don't know if it would matter with a hardened tool shank?

http://www.tormach.com/store/index.p...seratedcollets

Thanks
Terry

[keen]

Hi Terry - Yes I see those. They must grip more firmly due to the increased pressure points. This must mean more local wear to the collet and shank compared with conventional larger surface area collets.

Which in theory must mean they are less good for wear resistance and therefore long term precision....but better for gripping - I imagine that is the trade off. Cheers, Keen

[tmarks11]

Tormach has started offering Serrated 5C collets in their store. Anyone have any experience with these? Would it be a good or bad idea for the TTS collet? I believe the idea is to reduce slipping, but don't know if it would matter with a hardened tool shank?

These are 5C collets, not R8 collets. They won't fit in your spindle, and are not a replacement for the TTS collet.

It is meant to hold a cylindrical workpiece on the mill work table (with a 5C collet chuck) or in the lathe spindle (with a 5C chuck).

If you’ve ever had an issue keeping hot rolled steel, cast parts, or forged parts in your lathe or 4th axis, this is the collet for you. This serrated collet provides a tighter grip on hard-to-hold parts with internal and external threads that correspond to the 5C standard.

If they did offer serrated R8 collets, it would still not be sold as a replacement for holding endmills, but as something you could use to hold workpieces in the spindle (when using the mill as a lathe). On a hardened tool, the serrated grip would offer less holding force than the smooth collet, and would be more likely to damage your endmill.

[keen]

Hi Tim - Yes the design better suits uneven work holding, but Terry asks a fair question, that is, what if a high precision R8 3/4 version was used for TTS. - But I fear wear and then less accuracy would result too quickly. Keen

[LeeWay]

A solid surface will have better gription than a serrated one I think. That is why they tend to use slick tires when the pavement is dry in racing. Rods and material tolerances are usually far less than TTS or typical tooling. The serrated 5C can bite better into less hard material as well as allow for a wider range of clamping. I do not think it would be a good idea if you only dress the outside of the rod though. Those serrations may bite pretty deep depending on how soft the material and the tolerance of the fit.

[mountaindew]

What would be an application or reason for using a serrated 5c collet?
Also noticed Tormach offers optional cup holders " 35469 - Spray Bottle Holder Kit"

edit, Just read duh
Individual 5C serrated collets in sizes ranging from 1/2" to 1". Recommended applications include hot rolled steel, cast parts, and forged parts.

[MFchief]

Yeah, I knew they were 5C, just wondering if the underlying concept might be useful. I know that pull out occasionally jumps up and bites folks, so I thought it was worth asking about.

Terry