China High Purity Cemented Carbide Round Bar Blanks For IC Substrate & HDI PCB Micro Drills Manufacturer, Suppliers
Product Description
PCB Carbide Drill Blank — Grade Specifications
| Grade | Co (%) | Grain Size (μm) | Density (g/cm³) | Hardness | Application |
|---|---|---|---|---|---|
| KT308H | 8 | 0.3 | 14.55 | 2060 | Suitable for high-speed copper clad laminate (CCL) |
| KT305H | 5 | 0.5 | 14.92 | 2180 | Suitable for IC substrate machining |
| KT209 | 9 | 0.2 | 14.45 | 1960 | Suitable for general machining of various PCB boards |
Main sizes of drill blank rods: Φ1.0-330, Φ1.15-330, Φ1.3-330, Φ1.5-330, Φ2.0-330, Φ2.5-330
Note: Φ1.0-330 is the most widely used grade.
Product Description & Technical Advantages
This carbide rod blank is specially developed for high-end PCB drill bits. Supported by refined production equipment, mature processes, strict environmental control and premium raw materials, it features guaranteed precision, stability and purity, ideal for manufacturing high-precision micro drills and IC substrate drills.
Made via dedicated extrusion forming and 10MPa uniform-pressure sintering, the blank avoids uneven density and irregular microstructure. Consistent density and homogeneous grain structure across batches enable finished drill bits with high drilling accuracy, outstanding wear resistance and low breakage risk.
Produced in clean workshops with closed-loop temperature & humidity control, the material stays free from dust and impurities for reliable surface cleanliness and consistent quality. It is manufactured independently without mixing other carbide grades, eliminating cross-contamination and meeting strict purity requirements of micro drills and IC substrate drills.
It adopts high-purity WC powder from top-grade sources. With professional powder mixing and custom formula, the blend is uniform and stable to deliver high strength and toughness. Japan-sourced oil-based wax extrusion ensures even binder removal, preventing carbon residue and internal defects that cause drill bit performance loss and short service life.
Every production step, from high-purity raw material batching, precise mixing, extrusion forming, constant-temperature & constant-pressure sintering to clean handling, is finely controlled. These premium carbide rod blanks serve as dependable base stock for high-end PCB drills, ultra-micro drills and high aspect ratio precision drills.
KT308 Drill Bit Material Overview
1. Chemical Component (Wt%)
| Grade | WC (%) | Co (%) |
|---|---|---|
| KT308 | 91.8 - 92.8 | 7.2 - 8.2 |
2. Physical Properties
| Hardness (HV30) | Density (g/cm³) | TRS (N/mm²) | Grain Size (μm) | Porosity |
|---|---|---|---|---|
| 1960 - 2060 | 14.45 - 14.65 | ≥ 4500 | 0.3 | A02 B00 C00 |
3. Microstructure & 4. Application
Application: KT308 Grade is special used for PCB drill bits, recommended for cutting diameters ≤0.3 mm, High length-to-diameter ratio.
Frequently Asked Questions (FAQ)
KT308H offers an ultrafine grain size of 0.3 μm, high hardness (2060), and balanced cobalt content (8%). It is engineered specifically for high-speed copper clad laminate (CCL) machining and precision micro-drilling applications.
KT305H is the recommended grade for IC substrate machining. It features a lower cobalt content of 5%, grain size of 0.5 μm, and superior hardness of 2180, providing optimal rigidity and wear resistance.
The main available sizes are Φ1.0-330, Φ1.15-330, Φ1.3-330, Φ1.5-330, Φ2.0-330, and Φ2.5-330. Among these, the Φ1.0-330 specification is the most widely adopted in the PCB industry.
The 10MPa uniform-pressure sintering process eliminates internal defects, uneven density, and microstructural irregularities. This ensures homogeneous grain structure, reduces drill bit breakage, and ensures high precision during deep-hole drilling.
Cleanroom production with closed-loop climate control prevents ambient dust, airborne impurities, and grade cross-contamination, ensuring flawless surface cleanliness and consistent material purity for micro drills with cutting diameters ≤0.3 mm.
The oil-based wax extrusion method enables clean, even binder removal during debinding. This eliminates carbon residue and prevents internal structural defects, ensuring maximal tool life and sustained mechanical integrity.
