[deadlykitten]

hy gian go with bearing nuts so to avoid useles torque on the collet ( that leads to micro-damage and less clamping force ), and be sure that the tool shank that goes inside the collet is blank ( thus not coated ), cilindrical ( no flats ), and mount it dry ( not only clean, but also dry), and use a H7 collet ( designed for a h7 clamping range )

17k rpm : is there a balancing machine ? and what is the maximum rpm of your spindle ? you know, so to avoid killing your spindle at max rpm, with an unbalanced toolholder

like other said, a toolholder with a smaller collet may help ... if it fails, and you wish to buy a hydra holder, it is no guarantee that it will work; consider shrink-fit ( definetly lighter than a hydra ) or weldon ( cheaper, possibly the screws will fly out, so craft another ones with small play, and adjust your cutting specs acordingly, because they deliver a higher tool run out, and that means that your final mould surface won't be as nice as when machining it with a tool with less run-out, but it may still be ok/salable )

or it may be that your tools are poor quality : if possible, change them often / kindly

[mactec54]

hy gian go with bearing nuts so to avoid useles torque on the collet ( that leads to micro-damage and less clamping force ), and be sure that the tool shank that goes inside the collet is blank ( thus not coated ), cilindrical ( no flats ), and mount it dry ( not only clean, but also dry), and use a H7 collet ( designed for a h7 clamping range )

17k rpm : is there a balancing machine ? and what is the maximum rpm of your spindle ? you know, so to avoid killing your spindle at max rpm, with an unbalanced toolholder

like other said, a toolholder with a smaller collet may help ... if it fails, and you wish to buy a hydra holder, it is no guarantee that it will work; consider shrink-fit ( definetly lighter than a hydra ) or weldon ( cheaper, possibly the screws will fly out, so craft another ones with small play, and adjust your cutting specs acordingly, because they deliver a higher tool run out, and that means that your final mould surface won't be as nice as when machining it with a tool with less run-out, but it may still be ok/salable )

or it may be that your tools are poor quality : if possible, change them often / kindly

You have no clue the ER Bearing Nuts still need the same torque as a regular ER Nut, yes they work better and have a smoother lock up on the collet, so stop the Bs, they still need the same Torque to lock them up

Nothing changes only a smoother lock up action with a ER Bearing Nut, there are 2 types of ER Bearing Nuts, Friction Nuts has hardened inserts which slide and the other has hardened inserts that work like a bearing

The ones that last and work the best are the Hardened friction thrust washers, the bearing type fail after a short while of use, both types provide a higher lock up torque than a standard nut which should not be used for highspeed machining

[deadlykitten]

hy mactec, pls, be polite i was not refering to the torque required to tighten the nut, nor to that a bearing nut requires more/less torque to deliver same clamping force; in the end, each collet provider has it's own torque tables, that acts like a general guide line

i was only scratching the surface of that a normal nut, in time, leads to collet and chuck damage, because it has a tendency to rotate the collet, while a bearing type won't change collet 'phase'; thus, a bearing type has a higher chance to transform tightening torque into clamping force, since there is less friction

also, a low quality bearing nut won't behave as nice as a normal one crafted with more attention to thread tolerances ( including the thread on the toolholder )

whatever / kindly