1. Safety and Usage Precautions

• Avoid improper cutting conditions to ensure tool safety and longevity.
• Do not use tools exhibiting significant wear or chipping.
• Securely fix both tool and workpiece during machining to prevent accidents.
• Be aware of fire hazards from hot chips and sparks; use machine shielding and remove combustible materials.
• Avoid direct contact with cutting edges and rotating tools; wear protective equipment.
• Specifications may change without notice; unauthorized reproduction of catalog content is prohibited.

2. Recommended Cutting Conditions and Procedures

• Reduce feed rate by approximately 50% when machining corners to protect tool integrity.
• Use non-water soluble cutting fluids for improved performance and tool life.
• For achieving groove depth, use tools sequentially from shorter to longer neck lengths.

3. Cutting Parameters by Work Material

Detailed tables specify recommended rotation speeds (min⁻¹), feed rates (mm/min), and depths of cut (mm) for various materials:

• Carbon and Alloy Steels (150–250 HB)
• Stainless and Mold Steels (25–35 HRC)
• Pre-hardened Steels (35–45 HRC)
• Hardened Steels (45–55 HRC)

Parameters vary based on tool diameter, flute length, and neck length, tailored to material hardness and machining operation.

4. GS MILL Long Neck Ball Endmill Series Overview

• Designed for fine, deep milling of mold steels and difficult materials.
• Exceptional tool life—over twice that of competitors—due to ultra-fine grain carbide substrate, high transverse rupture strength, rigid design, and advanced multi-layer wear-resistant coatings.
• Superior surface finish enabled by proprietary cutting edge geometry and GS coating.
• Innovative ball nose shape with one-pass grinding ensures tight ball radius tolerance (+3 to -7 μm) and back taper design reduces cutting resistance and improves surface roughness.
• Extensive product lineup (364 items) to cover diverse fine machining needs.

5. Tool Design and Features

• Micro-grain carbide substrate offers high wear resistance and fracture toughness.
• Back taper reduces contact length between cutting edge and workpiece, lowering cutting forces.
• Seamless one-pass grinding ensures high dimensional accuracy and surface quality.

6. Performance Comparisons and Test Results

• Surface Roughness: GS MILL tools produce superior surface finish on vertical walls compared to competitors.
• Milling Displacement: After 1000 m milling, GS MILL tools show significantly less displacement (0.03–0.18 mm) versus competitors (up to 2.5 mm), indicating higher rigidity and precision.
• Tool Life: GS MILL tools maintain performance over longer cutting lengths (up to 4000 m) with less wear.
• Corner Wear: Lower corner wear in side milling compared to competitors under identical conditions.
• Surface Precision: Milling surface precision as low as 0.9 μm, outperforming competitors at 2.8 μm.

7. Recommended Milling Conditions for GS MILL Tools

• Cutting speeds typically range from 40 to 94 m/min depending on tool diameter and material.
• Feed rates vary from approximately 300 to 1150 mm/min with feed per tooth around 0.012 to 0.038 mm/tooth.
• Depth of cut generally small (0.01 to 0.5 mm) for fine machining.
• Recommended cutting fluids include oil-based or air blow depending on application.

8. Product Specifications

• Tool diameters range from 1.0 mm to 6.0 mm and above.
• Ball radius ranges from 0.5 mm to 3.0 mm.
• Neck length, cutting length, shank diameter, and overall length detailed per product.
• Helix angle fixed at 45°, relief angles specified.

9. Interference and Effective Length Data

Tables provide interference angles and effective cutting lengths relative to workpiece slope angles (0.5°, 1°, 2°, 3°), critical for avoiding machining collisions and maximizing cutting engagement.

Interference angles decrease with increasing tool diameter; effective lengths increase with workpiece slope angle.

10. Pricing and Packaging

• Prices inclusive of tax range approximately from 4,200 to 20,000 yen depending on tool size and series.
• Packaging standardized at 4 pieces per package.

11. Technical Data Summary for GS MILL Long Neck Two and Four Flutes

• Two-flute (GSN2) and four-flute (GSN4) variants available; four-flute tools recommended to use feed rates 1.5× higher than two-flute values for grooving and side milling.
• Dimensions include cutting edge length, neck length, overall length, neck diameter, outer diameter, and shank diameter with tight tolerances.
• Interference angles range approximately from 0.82° to over 11°, effective cutting lengths adjusted for workpiece slope.
• Prices range from approximately ¥3,850 to ¥20,000 inclusive of tax.

12. Milling Conditions by Material and Tool Type

13. Best Practices and Recommendations

• Use four-flute GSN4 tools with feed rates 1.5× higher than two-flute GSN2 tools for grooving and side milling to enhance productivity.
• Reduce feed rate by 50% when machining corners to protect tools.
• Use non-water soluble cutting fluids for improved cooling and lubrication.
• Sequentially use tools with increasing neck lengths to achieve desired groove depths effectively.
• Adhere strictly to specified tolerances and cutting parameters to optimize tool life and machining quality.
• Select tools based on interference angle and effective cutting length relative to workpiece slope to avoid collisions and maximize efficiency.

14. Manufacturer and Contact Information

Manufacturer: Nachi-Fujikoshi Corporation, Tokyo and Toyama Headquarters, Japan.

International Sales Contact: +81-3-5568-5241

Website: http://www.nachi-fujikoshi.co.jp

Multiple regional sales offices and distribution centers across Japan provide local support.

15. Conclusion

This document serves as a comprehensive technical catalog and guide for GS MILL Long Neck Series milling cutters, covering ball endmills, two-flute, and four-flute variants. It provides detailed tool specifications, machining parameters tailored to various steel materials, safety precautions, and operational recommendations to ensure optimal tool performance, longevity, and machining precision in fine mold manufacturing and related applications.