Kyocera 2,31 TA SGM07638 DRILL 2FL - Micro Hole Machining

Product Overview

The Kyocera 2,31 DRILL 2FL TA SGM07638 is a precision-engineered solid carbide micro drill designed for high-performance CNC holemaking operations. Manufactured from ultra-fine grain carbide substrate and finished with an advanced PVD TA coating, this tool delivers exceptional dimensional accuracy, superior surface finish, and extended tool life in demanding production environments.

With a nominal cutting diameter of 2,31 mm and a robust 2-flute geometry, the SGM07638 is optimized for drilling steel, stainless steel, and cast iron workpieces. The carefully engineered point geometry minimizes cutting forces and enhances centering capability, ensuring consistent hole quality from the first part to the last.

ISO Designation Breakdown

The catalog number SGM07638 follows the Kyocera solid round tool nomenclature system:

Engineering Dimensions & Geometry

Grade Details – Key Grade Characteristics

The TA grade applied to the SGM07638 is a premium PVD-coated micro-grain carbide specifically developed for general-purpose steel and stainless steel machining. Key characteristics include:

• Substrate: Ultra-fine grain tungsten carbide (0.5 μm grain size) with 12% cobalt binder for exceptional toughness and edge stability.
• Coating: Multi-layer PVD TiAlN-based coating with nano-structured architecture providing high oxidation resistance up to 900°C.
• Hardness: 92.0 HRA (1,600 HV) substrate hardness ensures wear resistance in high-speed drilling.
• Coating Hardness: 3,300 HV, minimizing abrasive wear and extending intervals between tool changes.
• Coefficient of Friction: 0.45, reducing built-up edge tendency and improving chip flow.
• Coating Thickness: 1–3 μm, optimized for micro tools to maintain sharp cutting edges.

Grade Comparison Matrix

Chipbreaker Profile

Although the SGM07638 is a solid carbide drill rather than an indexable insert, its flute geometry serves an analogous chipbreaking and evacuation function. The design features:

• Parabolic Flute Profile: Optimized flute form provides generous chip pocket volume relative to tool diameter, preventing chip packing in deep holes.
• Double Margin Design: Two narrow margins along the flute length provide burnishing action that improves hole surface finish and dimensional stability.
• Web Thinning: Advanced web thinning at the point reduces thrust forces by approximately 25% compared to standard chisel-edge designs, improving penetration rates.
• Positive Rake Face: A carefully ground positive rake angle along the cutting lip promotes efficient chip curling and reduces cutting temperature.
• Chip Splitting Grooves: Micro-grooves on the rake face break long chips into manageable segments, ideal for automated production with unmanned operation.

Recommended Applications & Workpiece Materials

Application Map by Operation

Recommended Cutting Conditions

Starting parameters for the 2,31 mm diameter TA grade drill. Adjust based on machine rigidity, coolant pressure, and hole depth.

Note: For hole depths exceeding 5×D, reduce feed by 20% and increase coolant pressure to minimum 30 bar. For stacked plates or cross-hole drilling, reduce feed to 50–70% at the intersection point.

Operating Guidelines

• Use internal coolant (minimum 20 bar) for holes deeper than 3×D to ensure effective chip evacuation.
• Maintain runout below 0.01 mm at the tool tip for optimal hole accuracy and surface finish.
• Apply peck drilling cycle for holes deeper than 5×D; retract to break chips every 1–2×D.
• Ensure workpiece is securely clamped; use center spot or pilot hole for diameters below 3 mm.
• Reduce cutting speed by 15–20% when machining stainless steels or heat-resistant alloys.
• Verify collet condition regularly; worn collets increase runout and reduce tool life significantly.

Toolholder Compatibility

Packaging & Ordering Information

Catalog Meta Data

All technical data and recommendations are based on Kyocera internal testing under controlled conditions. Actual performance may vary depending on machine condition, workpiece material consistency, and coolant quality. For application-specific support, contact our technical team.