A BT40 with a pull stud is a component that connects a BT40 tool holder to a CNC machine’s drawbar, allowing it to be securely held in the spindle. These are made of high-strength, heat-treated steel to ensure rigidity and safety, and they come in various head angles (like 45° or 90°) and thread sizes, often with or without a hole for through-spindle coolant.
Key features
- Function: The pull stud acts as a retention knob to connect the tool holder to the machine’s drawbar. The drawbar pulls the tool holder into the spindle’s taper to secure it.
- Material and construction: They are manufactured from special steel and are heat-treated for high rigidity and strength. A quality pull stud is crucial for performance and safety, as a failure can damage the machine, workpiece, or even injure an operator.
- Variations:
- Head angle: Common angles include 45° and 90°, which are designed to mate with the drawbar’s clamping mechanism.
- Coolant hole: Pull studs are available with a central hole (through-spindle coolant or TSC) or without one. The hole is necessary for machines that pump coolant through the spindle to the cutting tool.
- Thread: BT40 pull studs use metric threads, typically M16x2.0.
- Standards: They are designed to meet the MAS403-BT standard for tool holders.
- Application: They are used with BT40 tool holders in a wide range of CNC milling machines and vertical machining centers (VMCs).
