JM Performance Products Changes Material Used in Retention Knobs
Westec 2019: JM Performance Products has begun changing the material used in the production of its retention knobs from 8620H to 9310H grade steel.
JM Performance Products has begun changing the material used in the production of its retention knobs from 8620H to 9310H grade steel. The 9310H material offers 40% greater tensile strength, the company says, which is expected to meet changing milling demands. This change in material predominantly affects the 30- and 40-taper knobs, although some 50-taper knobs have been included.
The company’s high-torque knobs are designed to eliminate toolholder expansion, which is said to be the main cause of vibration, chatter, runout, poor tool life, poor tolerances and other milling issues.
Having identified a design flaw regarding the expected cross-sectional strength of the knobs, JMPP has begun modifying the size of the coolant holes in many of the 30- and 40-taper knobs. The knobs will continue to supply more coolant than demanded, but will be sized to increase the cross-sectional strength of the knobs.
As the retention knobs made from 8620H are phased out, they will be replaced by an HS (High Strength) version.
The retention knob is an unmistakably critical component of the machining process. However, the tightening of the knob itself can lead to the toolholder not seating securely in the machine. You may be losing tool life to knob tightness without even knowing it.
Angle heads can enable a three-axis machine tool to be more versatile. That said, this shop explains that there’s more to getting started using them than simply loading them into a machine’s spindle.
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.