Custom Tungsten Carbide Bushings — WC/Co, ISO K30
Precision-ground tungsten carbide bushings manufactured from WC 92% / Co 8% cemented carbide to customer specifications.
Eurobalt manufactures tungsten carbide components of any complexity based on customer drawings or technical specifications. Our production capabilities cover the full cycle — from powder pressing and sintering to precision grinding and final inspection. Below is one example of such work.
This project involved two types of magnetized tungsten carbide bushings for industrial use. Eurobalt delivered both part types through a complete in-house manufacturing cycle: trial production, sintering parameter validation, batch pressing, sintering, precision grinding, and laser marking.
Material
| Standard | Grade |
|---|---|
| ISO 513 | K30 |
| Composition | WC 92% / Co 8% |
The bushings are manufactured from cemented carbide (hardmetal) — a tungsten carbide composite with 8% cobalt binder, classified in the ISO K30 application group. This grade combines high hardness (89–90 HRA) with good impact toughness, making it suitable for wear-resistant components operating under cyclic loads.
| Property | Value |
|---|---|
| Hardness | 89–90 HRA |
| Density | 14.5–14.8 g/cm³ |
| Transverse rupture strength | ≥ 1500 MPa |
| Elastic modulus | ~540 GPa |
Dimensions
| Parameter | Bushing A | Bushing B |
|---|---|---|
| Outer diameter | 65 mm | 55 mm |
| Height | 35 mm | 49 mm |
| Weight (approx.) | 0.4 kg | 1.0 kg |
Production Process
The manufacturing cycle included five main stages:
Stage 1 — Trial Pressing
Eurobalt pressed a trial green compact to verify die performance and dimensional accuracy of the as-pressed part before committing to the full batch.
Stage 2 — Trial Sintering and Shrinkage Calibration
The trial compact was sintered to determine the exact shrinkage coefficient for this specific WC/Co composition. All critical dimensions and mechanical properties were measured to confirm the mass-production process parameters.
Stage 3 — Batch Pressing
With validated tooling and process data, our team pressed the full production batch of green compacts from WC 92% / Co 8% powder blend.
Stage 4 — Sintering
The green compacts were sintered at high temperature under controlled atmosphere. During sintering, the cobalt binder melts and wets the tungsten carbide grains, producing a fully dense hardmetal body with the required hardness and strength.
Stage 5 — Grinding, Inspection and Marking
After sintering, each bushing underwent precision grinding of all functional surfaces — outer diameter, inner diameter, end faces, and profile features — to achieve the specified dimensions and Ra 0.4 surface finish on critical bores. Every part was inspected and laser-marked for traceability.
Quality Control
- Dimensional inspection of all ground surfaces against drawing tolerances (ISO 2768-mK)
- Surface roughness verification (Ra 0.4 on bores)
- Hardness testing (target: 89–90 HRA per ISO 3878)
- Visual inspection for cracks, chips, and surface defects
- Magnetization direction verification
- Laser marking legibility check
Standards Reference
| Standard | Description |
|---|---|
| ISO 513:2012 | Classification of hardmetals — application group K30 |
| ISO 2768-mK | General tolerances — medium (m) for linear, coarse (K) for angular |
| ISO 3878 | Hardmetals — Vickers hardness test |
| ISO 3327 | Hardmetals — Transverse rupture strength |
| ISO 4499 | Hardmetals — Metallographic determination of microstructure |
| Completed | 2026 |
