[awjareme]

I have a couple sets of er40 cat40 collets that we use quite regularly for drills and such. Is there much advantage to getting a TG system for hold solid carbide endmills? Also whats the difference between 75 100, and 150?

[fizzissist]

I have a couple sets of er40 cat40 collets that we use quite regularly for drills and such. Is there much advantage to getting a TG system for hold solid carbide endmills? Also whats the difference between 75 100, and 150?

I've used ER32 and ER40 for holding solid carbide emills...fine for most jobs, but if you're going to push the tool all the way to it's capacity, look to a shrink system.
Personally, if you've already got an ER system, I see no point in spending more money on a TG system,.... too close to being redundant, with none of the advantages.

It's my understanding that the TG has somewhat greater gripping strength. How much, and how much advantage do you gain? Depends on your system.

Biggest disaster I ever had was a solid 3/4" mill in an ER40, clamped as tight as I could get it. Tool got sucked out the end of the holder and gave the bed of my mill a wonderful new decorative groove before I could slam the big red button....

Why? I'd pushed the tool all the way up against the screw stop in the holder...and as it got sucked into the holder while tightening, the torque I could apply was limited by the movement of the collet because of the tool hitting the stop. Ouch. Hard way to learn, especially since I'd never had that happen before. Almost a religious experience.

Will TGs do that? Dunno.

[awjareme]

ouch, what do you torque to? I've been trying to give them around 130 ft/lbs
I was also wondering about run-out with the different systems. I guess they must be similar? Maybe I will just stick to the ER for now, as i think heat shrink is getting a little bit too expensive.

[fizzissist]

Depending on the mfg of the ER collet/holder, the torque varies from 90ft-lbs to 146ft-lbs. My good torque wrench doesn't go that high, so I just crank on it till it makes me feel like I did a lot of work.

Outside of the shrink holder, a solid Weldon shank holder is good and rigid, and less expensive than the collet type.
One of the advertisers here, Glacern, has a decent selection... Have never used them, but the stuff at least looks good, and if their website is any indicator, the products should perform.

Glacern Machine Tools - Endmill Holders

[underthetire]

There is a reason why most carbide em's don't have the flat ground on them. They prefer you to run them in collets, or the collet style end mill holder. Our rigo fix stuff is good to about .0001 run out.

[dertsap]

most carbides come without a weldon because you'd be limited to the type of holder that you can use , if you put a weldon into a collet holder it will wreck the collet , and it would destroy a hydraulic holder
if a flat is needed then its simple to grind one but overall most decent manufacturers offer weldon if the customer prefers .
Personally I don't trust collet holders for anything above 3/8" of an inch and for the most part use sidelock for most of my machining processes . I've used a lot of styles of holders over the years and the only holders that i have not seen let a tool slip are sidelocks .

As far a collet preferences go then if I had to do heavy machining in a collet holder then I'd prefer a tg because the tool won't slip as easy as er , if i need tight tolerance finishing then I'd go er , if i want to drill the I prefer da holders because their smaller dia allowing better reach in tight areas , otherwise drill with er

.

[Shane1234]

i use set screw stuff on heavy machining, but if i were too worried about runout on heavy milling, i would change to hydraulic.

[awjareme]

I had always thought that a set screw holder was lind of sloppy as there has to be clearance for the tool to slide in, and also the slop in the set screw threads and the size of the notch itself vs the relatively soft set screw. I guess there is no chance of the tool slipping completely, i just always assumed some movement. Maybe simpler is better in this case

[Shane1234]

i either order my mills with side slots for the set screw or grind a flat on them, and i dont have any issues with heavy milling.

[dertsap]

if you grind the notch(flat) on a bit on an angle (deepest being on the flute side) then the screw will seat itself in a way that the tool will never move
decent holders can run with very little if not no runout , I've had times where i've run carbide drills in them with no troubles and the drills dialed perfectly .
sidelock over time will stretch but usually its on large diameters that have been reefed extremely tight over and over again

[RICHARD ZASTROW]

Find out if non pull-out collets are available in the style you want to use. They have a "plug" that seats into the Weldon type end mill shanks when the collet chuck is tightened. Hence, no pull out of end mill.

Dick Z

ADD: Kennametal has them in their Erickson TG series of collets.

[dertsap]

I've never had a chance to use them but I've heard that they work fairly well

[M01]

Tremendous Grip collets, or TG collets, were originally made by Erickson in USA and ER collets were introduced by Rego Fix in Switzerland. ER is now an ISO standard. ER collets are defined under DIN6499.

ER collets have a 16° included angle while TG collets have a 8° included angle, giving TG collets over twice the gripping force of ER collets.

The TG design is a true single angle collet, while ER is not, giving TG better inherit accuracy. Of course accuracy is also heavily influenced by the manufacturer of the chuck and collets.

TG chucks have a nut with rolling element thrust bearing while some ER Chuck nuts do and some do not. TG nut tightens on an ACME type thread and ER nut tightens on a conventional 60° thread, again making the TG more accurate.

TG collets are commonly available in 1/64" increments and also available in mm sizes.
ER collets are commonly available in 1mm increments and also available in 1/32' increments (and less commonly in 1/64” increments).
Both TG & ER are available in tap collets, with exact tap shank sizes and square drive at the bottom.
ER collets are claimed to have a 1mm gripping range however when collapsed down near the minimum (e.g. a 1/8" tool in a 4mm ER16 collet), the collet nut in some cases cannot extract the collet leaving the collet jammed in the chuck, requiring undesirable collet removal procedures. Using ER collet sets with smaller size increments (i.e. 0.5mm or 1/64”) eliminate this problem.

TG collets are available in ‘non-pull out’ which includes a extra part that engages in the flat of a Weldon (side lock) tool shank, however I have never experienced a tool pull out of a regular TG collet.

ER collets are made in these capacities:
ER8 (5mm max capacity, less common)
ER11 (7mm max capacity, common)
ER16 (10mm max capacity, very common)
ER20 (13mm max capacity, common)
ER25 (16mm max capacity, common)
ER32 (20mm max capacity, very common)
ER40 (26mm max capacity, very common)
ER50 (34mm max capacity, less common)
There are also ER9 (5mm max), ER12 (7mm max), ER60 (40mm max) and ER90 (60mm max) but these are very obscure.

TG collets are made in these capacities:
25TG (0.25” max capacity, uncommon)
50TG (0.5” max capacity, less common)
75TG (0.75” max capacity, common)
100TG (1” max capacity, very common)
150TG (1.5” max capacity, very common)
200TG (2” max capacity, less common)
There was also 38TG (0.375” max) but it is practically extinct.

Other tool holding collet chuck systems are:
SK (excellent gripping force & accuracy, less common, more expensive)
Universal Acura-Flex (excellent gripping force & accuracy, less common, more expensive)
DIN6388 / Ortlieb / OZ (excellent gripping force & accuracy, common system for manual milling machine chucks)
DA (Double Angle) Weak & inaccurate - Should be avoided.
Clarkson Autolock (obsolete, complicated, requires special tool shank) - Should be avoided.

The ER collet system is quite good however there are better systems available.
In my opinion, for 3/4" and larger capacity, the TG collet system is superior to the ER collet system in every way. For 1/2" capacity chucks, TG50 is superior to ER20, however ER20 are far more common. In sizes smaller than 1/2” capacity, ER is preferred due to availability of components. If greater gripping force and accuracy is desired with chucks smaller than 1/2", the SK collet system or Acura-Flex systems should be considered.