In the pursuit of high-precision machining, achieving a low surface roughness (Ra) value is often the ultimate goal. Wiper Inserts have become a game-changer in this field. They allow manufacturers to double the feed rate while maintaining the same surface quality, or maintain the feed rate to achieve a mirror-like finish.
However, using them correctly requires specific attention to detail. Below, we explore the core features of wiper technology and the 7 essential precautions for its application.
1. Core Features: How Do Wiper Inserts Work?
The primary difference between a Wiper insert and a traditional insert lies in the edge geometry.
▶Design: Wiper inserts typically feature a specialized "wiper flat" or a modified nose radius (often with a micro-negative rake angle or chamfer) adjacent to the cutting corner.
▶Mechanism: During the cutting process, this design performs a "secondary smoothing" or burnishing effect on the workpiece surface. It effectively presses down or cuts off the microscopic peaks (feed marks) left by the tool.
▶Result: When machining materials like Aluminum Alloys or Stainless Steel, wiper inserts can significantly improve the surface roughness (Ra value), often achieving a mirror-like effect that eliminates the need for subsequent grinding.
2. Precautions for Using Wiper Inserts
To maximize the benefits of wiper technology, operators must adhere to the following guidelines:
(1) Select the Correct Insert Material
Just like standard tools, the substrate material must match the workpiece.
▶Carbide Inserts: The most durable choice for machining Cast Iron or Steel components.
▶CBN (Cubic Boron Nitride): The superior choice for processing High-Hardness Alloys or Hardened Steel, offering excellent wear resistance and thermal stability.
(2) Optimize Cutting Parameters
The "Golden Triangle" of machining (Speed, Feed, Depth) behaves differently with wipers.
▶Cutting Speed (RPM/Vc): Excessive speed can generate too much heat, causing the wiper edge to fail. Conversely, a speed that is too low may result in unstable cutting action.
▶Feed Rate (fn): This is critical. While wipers allow for higher feeds, an excessively high feed rate will still leave visible tool marks. If the feed is too low, productivity suffers. Recommendation: Always adjust based on the insert manufacturer's specific data sheet.
▶Depth of Cut (ap): Wiper inserts are designed for finishing operations. Keep the depth of cut shallow. A cut that is too deep increases cutting forces and can degrade surface quality.
(3) Maintain Edge Sharpness
The wiper effect relies entirely on the precision of the edge geometry.
▶If the cutting edge is worn, chipped, or rounded, the "wiping" function fails.
▶Action: Regularly inspect the tool condition. Replace or re-grind the insert immediately upon detecting wear to ensure consistent surface quality.
(4) Eliminate Vibration and Shock
Wiper inserts generate higher radial cutting forces due to their contact area.
▶Risk: Vibration leads to chatter marks or "waviness" on the surface.
▶Solution: Ensure the machine tool is rigid, the fixture is secure, and the overhang is minimized. Use dampening devices if necessary.
(5) Effective Cooling and Lubrication
A proper coolant strategy is vital, especially when machining metals.
▶Benefits: Coolant extends tool life and improves the surface finish.
▶Warning: Dry cutting can lead to the formation of a Built-Up Edge (BUE), where material sticks to the tool. A BUE alters the tool geometry and destroys the wiping effect.
(6) Ensure Smooth Chip Evacuation
Chip control is often overlooked in finishing.
▶Risk: If chips accumulate or wrap around the workpiece, they will scratch the freshly machined surface.
▶Solution: Ensure chips are breaking properly and evacuating. Use high-pressure coolant or compressed air to keep the cutting zone clear.
(7) Rigid Workpiece Clamping
Stability is everything in precision finishing.
▶Risk: A loose workpiece not only compromises dimensional accuracy but can also cause sudden vibration, leading to insert chipping.
▶Action: Double-check clamping pressure and stability before the operation begins.
Conclusion
Wiper inserts are powerful tools for improving efficiency and surface quality. By selecting the right material, controlling parameters, and ensuring a stable setup, you can fully leverage the potential of this technology.
Need high-performance Wiper Inserts for your production? Contact our technical team today for a consultation on the best geometry for your specific application.
