In this post, Chuck Shive with Chips & Tips compares four types of tool holders: Nut and Collet, Hydraulic Clamping, Thermogrip (Shrink Fit), and Hydraulic Press Fit.
Tool holders can have a significant impact on machine performance from feed rates to edge finish. In this post, Chuck Shive with Chips & Tips compares four types of tool holders: Nut and Collet, Hydraulic Clamping, Thermogrip (Shrink Fit), and Hydraulic Press Fit. He discusses the advantages and disadvantages of each as well as their suggested uses, so the next time you tool up, you’ll know exactly what to use for your application.
Nut and Collet
The Nut and Collet tool holder is the most commonly used in the industry.
Advantages:
- Low cost.
- Readily available.
- Easy to change.
- Adaptable to use with many different shank sizes just by changing out the collet. The collets are available in almost any size.
Disadvantages:
- Does not have maximum gripping strength of the tool.
- Runout of the tool itself. This is how far the cutting tool rotates off its true axis.
Applications: The Nut and Collet is commonly used with all applications and all brands of equipment. It is best used where you have low axial force on the tool and tool runout is not as critical.
Hydraulic Press
The Hydraulic tool holder uses the force of hydraulics to expand the bore and then release it, allowing it to clamp back around the tool.
Advantages:
- Optimizes the expansion tolerances.
- Uses unique vibration dampening capabilities which provide smoother part finishes.
- Can increase tool life up to 60%.
- Easy to change out tooling without needing special equipment.
- Supports multiple shank sizes.
Disadvantages:
- Does not have maximum gripping strength of the tool.
- Runout of the tool itself (although better than the Nut and Collet style). Runout is how far the cutting tool rotates off its true axis.
- Runout and grip deteriorate with continued use of this tool holder and sleeve.
Applications: The Hydraulic Clamping style is best used where vibration dampening is needed.
Thermogrip or Shrink Fit
The Thermogrip (aka Shrink Fit) tool holder uses extreme clamping torque by expanding the bore with inductive heat.
Advantages:
- Low profile for getting into tight spots.
- Achieves maximum clamping force onto the router ball for excellent gripping strength of the tool.
- Very low runout of the tool, ensuring optimal cut quality.
- Great balance.
- Faster speeds.
- Extends tool life.
Disadvantages:
- Initial cost.
- Requires speciality equipment for heating and cooling of the holder.
- Holder fits one size shank only.
Applications: The Thermogrip (Shrink Fit) style works very well with 5-Axis applications when you are trying to reach into deep pockets or tight spots and a standard tool holder with a chuck nut is too large. Multi-flute tools and extremely small diameter tools obtain better sidewall finishes with this style. It is also for applications that need high grip strength, such as with phenolic machining, and/or low runout is required.
Hydraulic Press
The Hydraulic Press tool holder uses the force of hydraulics and uses collets for the highest gripping strength currently on the market.
Advantages:
- Excellent gripping strength of the tool.
- Only three micron runout of the tool.
- Great balance.
- High vibration dampening.
- Faster feed rates.
- Better cut quality.
- Longer tool life.
- Only requires a different collet versus different holders for various tool diameters.
Disadvantages:
- Initial cost.
- Requires specialty equipment for changing the tool.
Applications: The Hydraulic Press style is recommended when strong grip strength is needed, such as in phenolic machining and/or low runout is required. Multi-flute tools and extremely small diameter tools obtain better sidewall finish with this style.
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Interested in any of these tool holders or have other tooling questions? Just give our tooling department a call at: 704-508-7000, reach out via email: parts@cronsrud.com, or visit our tooling website: https://www.cronsrud.com/store/index.php
Or, if you’re struggling with any production issues and would like to see if we have a solution for you, please give C.R. Onsrud a call at: 704-508-7000 or reach out via email: info@cronsrud.com. We are happy to help you any way we can.
