For factory owners operating Heavy Cutting Machines or NC Lathes, "chatter" is a nightmare. When machining hard materials like titanium or 45# steel, vibration leads to catastrophic tool failure. Often, the culprit is not the machine base, but the selection of the CNC linear guide preload class.

Many standard CNC linear guides come with Z0 (Light Preload). While smooth, they lack the rigidity required to suppress resonance during deep-depth cutting.

To combat this, we recommend the HG Series. As a specialized heavy load ball type linear guide, the  series features a unique four-row circular-arc groove design.

This structure provides equal load ratings in all four directions—radial, reverse radial, and lateral. Whether your CNC linear guide is subjected to vertical plunging or lateral milling forces, the HG-TYPE block maintains uniform stability, making it superior to standard two-row alternatives.

The most critical specification for a heavy duty CNC linear guide is the Preload Class. For heavy cutting, you must specify ZB (Heavy Preload).

According to HIWIN technical specifications, ZB preload applies an internal force of 0.10C to 0.12C. This negative clearance eliminates play and significantly increases the guide's stiffness.

Let's look at a real-world example using the HGH45CA model, a popular choice for CNC linear guide retrofits:

• Model: HGH45CA
• Basic Dynamic Load Rating (C): 77.57 kN
• ZB Preload Calculation (0.12C): 77.57 kN × 0.12 ≈ 9.3 kN

This means the block grips the rail with over 9,000 Newtons of force, creating a rigid foundation that resists vibration.

Data shows that when heavy preload is applied, rigidity is doubled and elastic displacement is reduced by one half. In the precision world of CNC linear guides, this reduction in deflection is key to eliminating chatter marks.

Refer to the selection criteria below to determine if your application needs ZB preload:

While ZB preload offers superior rigidity, it requires strict maintenance. We recommend replenishing grease every 100 km or 3-6 months to ensure your CNC linear guide system lasts for years.

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