Premium High-Speed Steel Threading Dies | Precision 6g Class for Stainless & Alloy Steels

Problem: Edge Collapse and Thermal Deformation

In CNC automated production or heavy-duty manual threading, low-grade alloy dies often lose their cutting edge within a few minutes. As the friction temperature rises, the tooth profile softens, leading to "over-sized" threads and galled surfaces. For factories, this means a high rate of defective parts and constant machine downtime for tool replacement.

Cause: Insufficient Red Hardness and Asymmetrical Grinding

Standard carbon or low-alloy steels cannot maintain structural integrity above 250°C. In industrial threading, localized heat at the tooth crest can easily exceed this limit. Furthermore, non-ground dies often have irregular relief angles, causing uneven cutting pressure that leads to die chipping and "drunken" thread paths.

Solution: The HSS-M2 Fully Ground Advantage

Our HSS-M2 (W6Mo5Cr4V2) dies are vacuum heat-treated to achieve a superior hardness of HRC 63-66. This material is engineered for "Red Hardness," allowing the die to cut effectively even at temperatures up to 550°C. Every die is 100% CNC fully ground, ensuring a perfectly symmetrical 3.5-thread lead-in chamfer. This precision reduces the starting torque and guarantees a smooth, mirror-finish thread profile that passes the strictest gauge inspections.

Technical Specifications: HSS Metric Series (Standard O.D.)

Application: Engineered for Modern Manufacturing

• CNC Lathe Production: High concentricity makes these dies ideal for automatic threading in Swiss-type lathes and turning centers.

• Stainless Steel Fabrication: Specifically optimized for 200 and 300 series stainless steels when paired with proper lubrication.

• Aerospace & Automotive: Used for manufacturing high-tensile fasteners where thread fatigue resistance is critical.

• Maintenance & Toolrooms: The first choice for workshops requiring a single tool that can handle a vast variety of tough alloys.

Technical Depth: Why Fully Ground HSS Matters

1. Geometric Stability: Unlike cast or forged dies, our fully ground flutes have a consistent relief angle, which ensures the cutting force remains constant throughout the die's life.

2. Surface Integrity: The Ra 0.4 internal finish of the threading teeth prevents "built-up edge" (BUE), a common cause of thread tearing in gummy materials like aluminum.

3. Red Hardness: The high Tungsten and Molybdenum content creates a carbide structure that resists friction-induced softening better than any alloy tool steel.

Professional FAQ

Q: Why choose HSS-M2 over 9CrSi?

A: HSS-M2 is designed for machine use and harder materials. It lasts 10x longer in production environments and can handle much higher cutting speeds without losing its edge.

Q: Can these dies be used for threading Grade 8.8 or 10.9 bolts?

A: Yes. The HSS-M2 substrate is tough enough to thread pre-hardened alloy steels, provided a high-pressure sulfur-based cutting oil is used.

Q: What is the benefit of the "Split" in the die?

A: It allows for fine adjustment. By tightening the set-screw in your die stock, you can slightly compress the die to achieve a tighter thread fit (e.g., from 6h to 6g).

Q: Do you offer TiN coating for these HSS dies?

A: Yes. For high-volume production, we offer Titanium Nitride (TiN) coating, which increases surface hardness to 2300 HV and significantly reduces heat friction.