GS MILL End Mills Series Overview

The GS MILL series comprises a wide range of carbide end mills engineered for high-efficiency milling across diverse applications, including general-purpose, high-speed roughing, hardened material machining, and microfabrication. The product line features multiple variants such as two-flute, four-flute, ball nose, radius, slot, hard, roughing, heavy, and long neck types, each tailored for specific machining tasks.

1. Product Specifications and Dimensions

• Diameter range: 0.2 mm to 20 mm; radii from R0.1 to R6; cutting lengths adapted for various machining depths.
• Detailed product codes and page references facilitate tool identification and selection.
• Variants include GS MILL Hard, Hard Ball, Roughing, Heavy, Long Neck Hard Ball, Long Neck Ball, and Slot types.
• Tolerances: Diameter tolerances typically 0 to -0.015 mm or 0 to -0.033 mm; shank diameter tolerance h6; helix angles commonly 25°, 30°, 40°, or 50° depending on tool type.

2. Performance and Application Areas

• Applications cover general milling, high-speed roughing, machining hardened steels (up to 65 HRC), deep engraving, and microfabrication.
• Specialized designs reduce cutting resistance by up to 50% and burr height to one-third or less, enabling efficient machining even on small spindle centers.
• Slot end mills provide stable cutting with minimal vibration and burr formation, ideal for thin plates and pocket milling.

3. Material Compatibility

• Compatible with carbon steels (e.g., S45C, S55C), alloy and pre-hardened steels, hardened steels and die steels (up to 65 HRC), stainless steels (SUS304, SUS316), nickel and titanium alloys, cast irons, aluminum, and copper alloys.

4. Key Product Features and Benefits

GS MILL Heavy

• Optimized nick geometry halves cutting force.
• Enables deep cuts and high-efficiency semi-finishing with surface roughness below Rz10μm.
• New AlCr-based coating enhances lubrication, oxidation resistance, and tool life.

GS MILL Roughing and Roughing Radius

• Wave-type nick design stabilizes milling and reduces cutting resistance.
• Ultra-smooth TiAlN coating with micro-grain carbide substrate improves wear resistance and tool life.
• Supports stable grooving at feed rates above 1500 mm/min.

GS MILL Slot

• Three-flute design allows continuous drilling to pocket milling.
• Optimized groove shape minimizes vibration and burrs, suitable for low-rigidity or thin plate workpieces.
• New GS coating improves chip evacuation and tool life.

GS MILL Hard Ball

• Smooth coating reduces friction and enhances wear resistance.
• Ultra-micro grain carbide substrate with low cobalt content suppresses micro plastic deformation during high-speed machining.
• High-precision ball nose with +3 to -7 μm tolerance via one-pass grinding.
• Ideal for high-precision finishing of hardened mold steels (up to 60 HRC).

GS MILL Long Neck Series (Hard Ball, Ball, Two Flutes, Four Flutes)

• Designed for microfabrication in die and mold steels with tool life over twice that of competitors.
• High rigidity and multi-layer coatings improve wear resistance and fracture toughness.
• Back taper design reduces cutting resistance and improves surface finish.
• Seamless construction and droplet-free GS hard coating enhance sharpness and durability.
• Extensive selection with 546 series items for diverse micro-milling needs.

5. Performance Data and Comparative Analysis

• Cutting force reduced by ~50% in GS MILL Heavy and Roughing types compared to competitors.
• Burr height reduced to one-third or less, improving post-machining quality.
• Wear resistance tests show significantly lower wear and chipping rates for GS MILL Roughing and Hard Ball tools.
• Tool life tests indicate GS MILL Long Neck Hard Ball lasts 1.5 times longer than competitor tools when machining high-hardness steels (e.g., SKD61 at 53 HRC).
• Surface roughness: GS MILL Heavy achieves superior finish (Rz 5.3 μm) versus conventional roughing tools (Rz 33.6 μm).
• Stable milling at high feed rates (up to 2000 mm/min) with minimal chipping and breakage for GS MILL Roughing.

6. Recommended Cutting Conditions

• Cutting speeds typically range from 40 m/min to 80 m/min depending on tool and material.
• Feed rates optimized per tool type, e.g., 0.012 mm/tooth for micro tools, up to 0.1 mm/tooth for roughing tools.
• Cutting fluids: air blow standard; oil-based and water-soluble fluids recommended depending on application.
• Depths of cut and milling lengths specified per tool and workpiece hardness to maximize tool life and machining quality.

7. Best Practices and Recommendations

• Select tool type based on machining purpose: roughing, semi-finishing, finishing, or microfabrication.
• Use GS MILL Heavy for high-efficiency semi-finishing with improved surface quality.
• Employ GS MILL Roughing for stable high-feed grooving and rough machining with extended tool life.
• Choose GS MILL Slot for multifunctional operations from drilling to pocket milling with minimal vibration and burrs.
• Apply GS MILL Hard Ball and Long Neck Hard Ball for high-precision finishing of hardened steels with superior durability.
• Maintain recommended cutting speeds and feeds to optimize tool life and machining performance.
• Utilize appropriate cutting fluids and cooling methods to reduce tool wear and improve surface finish.

8. Detailed Tool Types and Features

• GS MILL Long Neck Ball (GSBN2): Excellent corner wear resistance and surface finish (0.9 μm roughness vs. 2.8 μm competitor).
• GS MILL Two Flutes (2GS): Stable side milling and grooving at feed rates up to 1000 mm/min.
• GS MILL Four Flutes (4GS): Multi-functional groove and side milling with high feed rate capability.
• GS MILL Radius (GS4-R): Enhanced GS coating for heat resistance and high-speed machining in hardened steels.
• GS MILL Hard (GSH series): Al-Ti-Cr multilayer GS Hard Coat with over three times oxidation resistance at 1100°C, improved wear resistance, and durability for super-high-speed milling in hardened die and mold steels.

9. Machining Conditions and Parameters

• Cutting speeds range from 50 m/min to 800 m/min depending on tool and material hardness.
• Feed rates vary widely, from 190 mm/min to over 10,000 mm/min based on tool and material.
• Wet machining recommended for stainless steels, nickel alloys, and titanium alloys; air blow standard for others.
• For stainless steel grooving, reduce spindle speed to 60% and feed to 40% of standard values.
• Adjust cutting parameters if vibration or abnormal sounds occur.

10. Tolerances and Quality Control

• Diameter tolerances: typically 0 to -0.015 mm or 0 to -0.033 mm.
• Shank diameter tolerance: h6 standard.
• Ball radius tolerances: ±0.01 mm or tighter.
• Helix angles standardized per tool type (commonly 25°, 30°, 40°, or 50°).

11. Dimensional and Interference Data for Long Neck Tools

• Detailed dimensions include outer diameter, neck diameter, shank diameter, ball radius, neck length, blade length, and overall length.
• Interference angles and effective cutting lengths are provided relative to workpiece slope angles (0.5°, 1°, 2°, 3°) to avoid collisions and optimize machining accuracy.
• Tools grouped by shank diameter series (e.g., 4 mm, 6 mm).

12. Pricing and Product Codes

• Extensive product codes listed for all tool types and sizes.
• Prices range approximately from 3,850 JPY to over 50,000 JPY depending on tool size, type, and specifications.

13. Operational Recommendations and Safety

• Use highly rigid machining centers and tool holders for stable and precise machining.
• Minimize tool overhang to reduce deflection and improve accuracy.
• Apply wet machining for stainless steels, nickel alloys, and titanium alloys to enhance tool life and surface finish.
• Reduce feed rates during corner machining to prevent tool damage and improve finish.
• Sequentially use tools with increasing neck lengths for deep groove machining.
• Ensure secure clamping of tools and workpieces; avoid use of worn or chipped tools.
• Be aware of fire hazards from hot chips or sparks; use machine guards and keep combustible materials away.
• Avoid direct contact with cutting edges and rotating tools to prevent injury.

14. Summary

The GS MILL series represents a global standard in carbide end mills, combining advanced geometries, innovative coatings, and precise manufacturing tolerances to deliver superior wear resistance, reduced cutting forces, extended tool life, and excellent surface finishes. The series supports a broad range of materials and machining conditions, including demanding applications such as hardened steel mold fabrication and micro-milling. Comprehensive technical data, including detailed product specifications, cutting parameters, and best practice recommendations, enable users to optimize tool selection and machining performance for diverse industrial needs.