High-Accuracy Metric Core Drill Bits | Perfect Concentricity for Precision Engineering

Problem: The Cost of Secondary Finishing

Many industrial workshops suffer from "rough" holes. When a drill produces burrs or an inaccurate diameter, workers have to spend extra time deburring or reaming the hole so that bolts can fit. In high-precision assembly, a hole that is even 0.1mm out of round can lead to structural rejection and massive financial loss.

Cause: Vibration & Asymmetrical Cutting

Inaccurate holes are usually caused by asymmetrical grinding. If one cutting tooth is slightly higher than the others, the tool will "walk" or vibrate. This vibration creates a jagged surface finish and forces the hole to become oversized, making it impossible to achieve a precision fit.

Solution: Full CNC Multi-Cut Geometry

We manufacture our cutters using state-of-the-art 7-Axis CNC grinding centers. This ensures every tooth is perfectly symmetrical. Our unique Three-Stage Cutting Geometry shears the metal in layers, resulting in a mirror-like finish on the hole wall. The precision is so high that secondary deburring is almost never required.

Technical Parameters

• Manufacturing Process: 100% Fully CNC Ground

• Tooth Geometry: Triple-Edge (Internal, Middle, External)

• Diameter Accuracy: +0.02mm / -0.00mm

• Surface Finish: Ra 1.6 - 3.2

• Concentricity: <0.05mm

• Material: HSS-M2 / M35

Application: Precision Assembly & Custom Fabrication

This series is designed for aerospace ground equipment, custom automotive chassis work, and high-end architectural metalwork. It is the preferred choice for labs and medical device manufacturers where every thread and bolt-hole must be perfect.

Selection Guide

When the project specification calls for "Burr-Free" or "Precision Fit," this CNC Ground series is the only choice. It is particularly effective for thinner materials where "tearing" is a common problem with lower-quality cutters.

Professional FAQ

Q: Why does the hole look polished?

A: Our triple-edge geometry cuts the metal cleanly rather than ripping it, which results in a much smoother surface.

Q: Does this help with bolt alignment?

A: Absolutely. The perfect roundness ensures that bolts pass through multi-layered plates without resistance.

Q: Is the shank also ground?

A: Yes, the Weldon shank is precision ground to ensure zero-slip and perfect alignment in the drill chuck.

Jiangsu Xing Rui Precision Tools Co., Ltd. is a leading manufacturer of high-quality cutting tools in China, established in 2008 and located in Danyang, Jiangsu Province—a major hub for cutting tool production with convenient transportation for global logistics.

Main Products

We specialize in precision cutting tools and accessories for industrial, construction, metalworking, and woodworking applications. Key product categories include:

• HSS Twist Drill Bits, SDS Drill Bits, and Woodworking Drill Bits
• HSS Machine Taps, Hand Taps, and Spiral Flute Taps
• Hole Saws, End Mills, TCT Hole Cutters, TCT Saw Blades, Diamond Saw Blades
• Drill Bit Sets, Taps & Dies Sets, Screwdriver Bits

Manufacturing Capability & Customization

• Over 90 CNC machines for high-precision production
• OEM & ODM services
• Support for special sizes and non-standard tools
• Strict quality control ensures dimensional accuracy and cutting performance

Global Market

Our products are exported to North America, Europe, South America, the Middle East, Southeast Asia, and Australia, serving tool brands, distributors, wholesalers, and industrial buyers worldwide.

Why Choose Xing Rui

• 18+ years of experience in cutting tool manufacturing
• Complete product range covering multiple applications
• Stable quality control system
• Competitive factory-direct pricing
• Support for small and large orders
• Fast production and on-time delivery

Partner with Xing Rui for reliable cutting tool solutions and long-term global business growth.