What's new
What's new

Are milling chucks obsolete?

The Nikken SK collet chucks come with a tightening handle that is six inches long so we’re probably sub 40 ft pounds and have runout values under .00025 100% of the time.
I used to use a torque wrench to tighten nuts until I got a few of these wrenches from Nikken and tested the consistency of hand tightening using them. I found that the torque was always between 35 and 40ftlbs and decided to stop using the bulkier torque wrenches. I also work with a machinist that usually tightens to around 25ftlbs for ER16/SK10 and he never has any issues and outputs fine work. I can see the value of a torque wrench for production shops and consistency, but I don't think anymore that it's that important for lower volume shops where jobs are usually done before any tools wear out.
 
What improvements have you noticed switching from side lock to hydraulic?
The runout is much better, which can be heard in the sound as well as seen in the finish. Finish was not much of an issue in roughing anyway, but I often use the same tool for the finish cut in aluminum. It is worth the extra money in my opinion and opens up more tool options when you don't need a flat on the shank.

The biggest downside to using hydraulic holders for me is the minimum length that must be inserted into the holder. 12mm and 1/2" holders typically say they need about 1.5" minimum tool depth on the data sheet. A lot of smaller diameter tools are only 1.5" long to begin with. I often need every bit of reach I can get, so I end up using ER collets quite often.
 
Last edited:
I used to use a torque wrench to tighten nuts until I got a few of these wrenches from Nikken and tested the consistency of hand tightening using them. I found that the torque was always between 35 and 40ftlbs and decided to stop using the bulkier torque wrenches. I also work with a machinist that usually tightens to around 25ftlbs for ER16/SK10 and he never has any issues and outputs fine work. I can see the value of a torque wrench for production shops and consistency, but I don't think anymore that it's that important for lower volume shops where jobs are usually done before any tools wear out.
Yeah, if you're skilled and reasonable, you can get away without it. But if you have a guy banging on it with a hammer or using a cheater bar, hand him a torque wrench.
 
2 Cents:
Another thing to consider when buying Taiwanese holders is the metal quality, I have thrown away all my Taiwanese holders, they were all great, in spec. but would get a lot of corrosion on the pull stud over time.
When we had experienced tool pullout on ER it ended up being a drastic detail, how well it was cleaned, once we started to clean the tool shank and the collet with Alcohol, we drastically reduced pullout.
I try to buy the shortest gauge length tool holders also, have a couple Schunk Tendo ES holders, great, once again never had pullout, but we clean the parts with Alcohol.
I just saw some hydraulic holders from a company Mapal (Germany) they had some short 50mm gauge length high torque hydraulics for $300 from $520, looked legit.
bought 1 and then a dozen. With the chamfer at the tip and the short length they align with our 1.75" gauge length Mari ER20 holders perfectly, coolant hits exactly the same spot on the cutter.
Have been roughing for a couple weeks with them, no issue.
1672627261875.png
1672627500572.png
 
2 Cents:
Another thing to consider when buying Taiwanese holders is the metal quality, I have thrown away all my Taiwanese holders, they were all great, in spec. but would get a lot of corrosion on the pull stud over time.
When we had experienced tool pullout on ER it ended up being a drastic detail, how well it was cleaned, once we started to clean the tool shank and the collet with Alcohol, we drastically reduced pullout.
I try to buy the shortest gauge length tool holders also, have a couple Schunk Tendo ES holders, great, once again never had pullout, but we clean the parts with Alcohol.
I just saw some hydraulic holders from a company Mapal (Germany) they had some short 50mm gauge length high torque hydraulics for $300 from $520, looked legit.
bought 1 and then a dozen. With the chamfer at the tip and the short length they align with our 1.75" gauge length Mari ER20 holders perfectly, coolant hits exactly the same spot on the cutter.
Have been roughing for a couple weeks with them, no issue.
View attachment 382967
View attachment 382968
That's strange, are you saying the tool holders themselves were OK and it was just the pull studs that corroded? Or both?
If the tool holders were all good and in spec, assuming they were fairly cheap, I would consider that a win. Pull studs are iffy though, especially on a BT30 where a snapped pull stud can trash a spindle. I'll have to ask the machine tool engineers around here which companies to avoid and which to buy from when it comes to pull studs.

I have a few dozen tool holders and since I don't really take any precautions to prevent rust, and I leave them sitting out in a high-humidity warehouse type factory, most of my tool holders get some rust or corrosion over time. It's not a dry reddish brown rust with deep pits, its more like speckled discolored spots that come off with steel wool. I hope the steel wool doesn't screw up the taper too much, but it definitely restores the outside steel surfaces to a good finish.

On the subject of corrosion, I'm still baffled as to why tool holder manufacturers haven't started PVD/CVD coating their tool holders, collets, nuts, pull studs, etc. The only example I can find is Nikken putting a TiN washer in their collets to act as a lower friction bearing. I don't see why they can't just DLC coat the entire collet nut to get the coefficient of friction down to like 0.1. Everything that's steel gets rusty eventually, but I've never seen rust on a PVD or CVD coated part.

I'll see if I can import a few Maritool BBT30 hydraulic holders, they look like they check all the boxes for what I need. All the Maritool holders I bought in the past were flawless.
 
That's strange, are you saying the tool holders themselves were OK and it was just the pull studs that corroded? Or both?
If the tool holders were all good and in spec, assuming they were fairly cheap, I would consider that a win. Pull studs are iffy though, especially on a BT30 where a snapped pull stud can trash a spindle. I'll have to ask the machine tool engineers around here which companies to avoid and which to buy from when it comes to pull studs.

I have a few dozen tool holders and since I don't really take any precautions to prevent rust, and I leave them sitting out in a high-humidity warehouse type factory, most of my tool holders get some rust or corrosion over time. It's not a dry reddish brown rust with deep pits, its more like speckled discolored spots that come off with steel wool. I hope the steel wool doesn't screw up the taper too much, but it definitely restores the outside steel surfaces to a good finish.

On the subject of corrosion, I'm still baffled as to why tool holder manufacturers haven't started PVD/CVD coating their tool holders, collets, nuts, pull studs, etc. The only example I can find is Nikken putting a TiN washer in their collets to act as a lower friction bearing. I don't see why they can't just DLC coat the entire collet nut to get the coefficient of friction down to like 0.1. Everything that's steel gets rusty eventually, but I've never seen rust on a PVD or CVD coated part.

I'll see if I can import a few Maritool BBT30 hydraulic holders, they look like they check all the boxes for what I need. All the Maritool holders I bought in the past were flawless.
My Tawaniese rust was holders and pull studs both. The Maritool BBT30 hydraulics have a statement that they arent for roughing, finishing only. Thats why I mentioned the Mapal high toque, they mentioned higher torque than shrink fit and ER.
 
This endmill L/D ratio looks horrible, it has like 7 flutes, and its cutting steel somehow. Definitely some magic goin on here.
 
On the subject of corrosion, I'm still baffled as to why tool holder manufacturers haven't started PVD/CVD coating their tool holders, collets, nuts, pull studs, etc. The only example I can find is Nikken putting a TiN washer in their collets to act as a lower friction bearing. I don't see why they can't just DLC coat the entire collet nut to get the coefficient of friction down to like 0.1. Everything that's steel gets rusty eventually, but I've never seen rust on a PVD or CVD coated part.


Done for ID purposes and not corrosion resistance...

Most tool holders don't rust because they run in an oil bath, then come out of that oil bath and stay covered in said oil for their entire lives. PVD is just an unnecessary step for all but shops in the most humid environments with almost no care to mitigate the problem. Like, it's fine if Big Diashowa or Rego wants to offer PVD, but you know any of the holder companies are going to charge an extra $100 for it.
 
That's strange, are you saying the tool holders themselves were OK and it was just the pull studs that corroded? Or both?
If the tool holders were all good and in spec, assuming they were fairly cheap, I would consider that a win. Pull studs are iffy though, especially on a BT30 where a snapped pull stud can trash a spindle. I'll have to ask the machine tool engineers around here which companies to avoid and which to buy from when it comes to pull studs.

I have a few dozen tool holders and since I don't really take any precautions to prevent rust, and I leave them sitting out in a high-humidity warehouse type factory, most of my tool holders get some rust or corrosion over time. It's not a dry reddish brown rust with deep pits, its more like speckled discolored spots that come off with steel wool. I hope the steel wool doesn't screw up the taper too much, but it definitely restores the outside steel surfaces to a good finish.

On the subject of corrosion, I'm still baffled as to why tool holder manufacturers haven't started PVD/CVD coating their tool holders, collets, nuts, pull studs, etc. The only example I can find is Nikken putting a TiN washer in their collets to act as a lower friction bearing. I don't see why they can't just DLC coat the entire collet nut to get the coefficient of friction down to like 0.1. Everything that's steel gets rusty eventually, but I've never seen rust on a PVD or CVD coated part.

I'll see if I can import a few Maritool BBT30 hydraulic holders, they look like they check all the boxes for what I need. All the Maritool holders I bought in the past were flawless.
NT Tool used to nickel-plate their holder bodies and then grind it off on the taper and bores.
So you got a fair protection from the surface corrosion. But I don't know if they are still made in that way.
 
So I'm wondering, in what circumstances are milling chucks the best choice? Will they outperform the collet holders and sidelocks in a BT30?
Some of the older styles are being phased out. The TG style collets are no longer produced by Kennametal and are getting hard to find, especially with the pin drive to keep the end mill from pulling down.
 








 
Back
Top