Process & Material
Pure Tungsten Small Hole EDM Drilling Feasibility Review
Pure Tungsten can be machined with Small Hole EDM when the geometry matches small through holes, deep holes, angled holes, cooling holes, vent holes, and start holes in hard or heat-resistant alloys. Pure Tungsten is a very high-melting refractory metal with high stiffness and brittle edge behavior at room temperature; the supplied condition affects support, discharge energy, finishing, and inspection.
Quick Answer
Small Hole EDM is suitable for Pure Tungsten when the feature is a small, deep, angled, cooling, vent, or start hole in conductive material. The supplied condition must be stated before tolerance and surface requirements are confirmed.
Key Material Decisions
How This Material Behaves
A very high-melting refractory metal with high stiffness and brittle edge behavior at room temperature. In Small Hole EDM, the supplied condition changes bore stability, breakthrough quality, wall finish, and the inspection plan for straightness and position.
Choosing the Right Condition
Choose Small Hole EDM for small through holes, deep holes, angled holes, cooling holes, vent holes, and start holes in hard or heat-resistant alloys. State the exact Pure Tungsten condition, then set tolerance, finish, support, and inspection from the controlled feature rather than the whole part.
Risks to Manage
For Small Hole EDM, breakthrough can chip the exit rim and hide subsurface damage along the wall, so both ends require microscopic inspection. The far end of the hole can drift even when the entry diameter and start position remain stable during the final portion of a high-aspect-ratio hole; acceptance must focus on grain boundaries, brittle rims and subsurface damage zones. On Pure Tungsten, the resulting defect can be exit-rim chipping and hidden wall damage despite acceptable entry size. For Pure Tungsten, use conservative discharge energy, strong local support and microscopic inspection of edges and subsurface damage. Verify both ends of the hole and use sectioning or suitable wall inspection where service risk requires it; document geometry, chipping, grain pullout and subsurface cracking for Pure Tungsten.
How Small Hole EDM Works on Pure Tungsten
Small Hole EDM advances a rotating tubular electrode through Pure Tungsten while dielectric exits at the cutting tip. Electrode wear, runout, internal flushing, true hole depth and breakthrough support control entry-to-exit diameter, taper, straightness and wall condition. Hole diameter, depth and depth-to-diameter ratio—not stock thickness alone—define the process limit.
Small Hole EDM Capability Reference
| What you're asking | What you can expect |
|---|---|
| Feature types | small through holes, deep holes, angled holes, cooling holes, vent holes, and start holes in hard or heat-resistant alloys |
| Tolerance | ±0.010–0.050 mm |
| Surface finish | Hole-wall finish is feature-dependent |
| Typical diameter | About 0.3–3.0 mm for ordinary planning |
| Depth driver | Depth-to-diameter ratio, straightness, and breakthrough |
| Main limitation | Very small diameter combined with extreme depth may require specialized equipment, staged electrodes, and dedicated metrology. |
Material Condition Reference
| Condition | What to expect | Watch out for | Surface notes |
|---|---|---|---|
| as-sintered or supplied condition | Use low-force fixturing and conservative discharge energy. | Brittle edges can chip or binder-rich zones can erode unevenly. | Inspect edge breakout and surface integrity rather than Ra alone. |
| stress-relieved or recrystallized | Use stable support and reduced energy on finished stock. | Grinding stress or porosity can cause local cracking. | Apply selective polishing or lapping where practical. |
How This Material Behaves
Pure tungsten is extremely refractory, stiff, and brittle. In EDM, this means sharp edges and thin sections can chip or microcrack under thermal shock even though no cutting force is applied. Use conservative pulse energy, avoid abrupt section changes where possible, and inspect critical edges by microscopy after final finishing. For Small Hole EDM, breakthrough can chip the exit rim and hide subsurface damage along the wall, so both ends require microscopic inspection.
Surface Integrity and Post-Process
For Small Hole EDM on Pure Tungsten, use conservative energy, strong support and inspection focused on edge chipping and subsurface damage. Reduce discharge energy near final size and breakthrough, then evaluate entry, exit, taper and wall condition separately. For fatigue-, flow- or seal-critical holes, specify recast acceptance or post-process cleaning and finishing instead of relying on diameter alone.
Pure Tungsten Small Hole EDM Checkpoints
- Confirm that the feature matches small through holes, deep holes, angled holes, cooling holes, vent holes, and start holes in hard or heat-resistant alloys.
- State the supplied condition: as-sintered or supplied condition and stress-relieved or recrystallized.
- Mark the controlled dimensions, functional surfaces, datum scheme, and inspection method.
Typical Parts and Features
- wear inserts
- high-temperature contacts
- hard-metal nozzles
- turbine-blade cooling holes
- mold and die vent holes
- injector and nozzle holes
Limits and Better Alternatives
Main Limit
Hole depth, diameter, aspect ratio, flushing, and breakthrough quality—not stock thickness alone—set the practical limit. On Pure Tungsten, edge chipping and subsurface damage require strong support and low-energy finishing; the supplied condition still controls support, finishing, and surface-integrity review.
Consider Another Route When
Use mechanical drilling when the tool can reach economically, laser drilling for suitable thin geometry, or Micro EDM for smaller precision holes.
Practical Next Step
Send the Pure Tungsten drawing with condition, controlled geometry, tolerance, functional surface callouts, quantity, and inspection requirements. If the route is unclear, we will compare Small Hole EDM with the adjacent EDM or conventional process.
Practical Takeaway
Pure Tungsten is compatible with Small Hole EDM when the feature matches the process access. The supplied condition determines support, finishing, surface control, and inspection.
Technical Reference
Use the values as planning references and define the functional requirement on the controlled drawing.
Use This Guide to Prepare Your RFQ
Contact us when your drawing and requirements are ready for review.
- Process: Small Hole EDM
- Material: Pure Tungsten
- Drawing or part sketch
- Material grade
- Thickness / part size
- Quantity
STEP/STP, DXF, DWG, PDF, IGS/IGES or ZIP.
Confidential drawing review. NDA support available on request.