Video: Safe Shrink-Fit Has Built-in Cooling
The cycle for heating the toolholder also includes water cooling so the toolholder finishes cool.
A shrink fit toolholding system heats the toolholder to expand the bore, then allows the cooling of the toolholder to shrink the bore around the tool shank and clamp it. Safety is a concern—users wear heavy gloves to avoid contact with a still-hot toolholder. This video from Techniks shows a shrink fit system supplied by the company that addresses that concern. As part of the heater’s cycle, the toolholder disappears briefly into the housing of the unit, where it is soaked with water. The toolholder is cool enough to touch by the time this cycle is complete.
Horn USA has developed quick-change tooling systems to drastically reduce set-up and toolchange times for Swiss-type lathes, including those with through coolant.
I’ve said that the toolholder is the least appreciated element in many milling processes, but the pull stud (or retention knob) is perhaps the least appreciated component of the toolholder.
Companies concerned about strict quality requirements regularly check toolholder tapers for wear or inaccuracy because these conditions can jeopardize the results of a critical operation. However, a shop can check tapers quickly and reliably with air gages. These devices can be used effectively without special operator training. For measuring taper in a production environment, few other methods can match the speed and performance of air, as multiple-circuit air jets can be placed in very small taper gages.