EDM Service
Titanium Grade 2 Sinker EDM Surface Integrity Review for Precision Fixtures
For Precision Fixtures, Sinker EDM can produce the required conductive features in Titanium Grade 2, but a low Ra value does not approve the surface by itself. Recast, micro-cracks, edge damage, corrosion or fatigue risk, and post-processing must be released as separate requirements.
Quick Answer
For Sinker EDM on Titanium Grade 2 in Precision Fixtures, approve the functional surface in separate steps. First verify geometry and roughness. Then verify recast or crack acceptance, edge condition, and any corrosion, fatigue, or post-process requirement that the application actually needs.
Key Surface Decisions
Why Surface Integrity Matters Here
The highest application risk is datum mismatch, flatness change after heat treatment or burrs on mating edges. A defect on that functional face can shorten service life, compromise the application requirement, or force rejection even when the overall dimensions are correct.
How to Specify Surface Requirements
Define surface acceptance for Precision Fixtures by separating roughness, recast, cracks, edge condition, and post-processing. For the Sinker EDM feature in Titanium Grade 2, identify datum, hole/slot position, flatness, state the exact material condition, and assign an inspection method to each accepted item.
What Gets Missed
The most common acceptance error is releasing the Precision Fixtures part from roughness or size alone while recast, edge damage, or sub-surface cracking remains on the named functional face. For Titanium Grade 2, a dimensionally correct feature can still be rejected for recast, contamination, or fatigue-sensitive edge damage. In Sinker EDM, the cavity floor can dish, corners can grow, and deep ribs can vary when electrode wear or debris evacuation is not controlled.
Why the Process Affects the Surface
A shaped graphite or copper electrode approaches the conductive workpiece in dielectric fluid without touching it. Pulsed discharges remove microscopic craters, the dielectric deionizes between pulses and carries debris away, and electrode undersize plus orbit motion control cavity size and compensate for wear. For Sinker EDM on Titanium Grade 2 in Precision Fixtures, the release plan must connect the named functional face to datum, hole/slot position, flatness.
Sinker EDM Capability Reference
| What you're asking | What you can expect |
|---|---|
| Feature types | blind cavities, ribs, shaped pockets, mold details, deep forms, and internal geometry that a traveling wire cannot reach |
| Tolerance | ±0.008–0.030 mm |
| Surface finish | Ra 0.2–6.3 μm |
| Electrode choice | Graphite or copper selected from cavity, finish, and wear needs |
| Primary cavity limit | Depth, rib width, access, and debris evacuation |
| Main limitation | Electrode access and debris evacuation limit deep, narrow blind geometry. |
Precision Fixtures Surface Planning
| What matters | What to expect |
|---|---|
| Typical parts | locator plates, alignment blocks, pin seats, and inspection nests |
| Functional requirement | repeatable datums, pin and bushing locations, wear surfaces and alignment features |
| Main failure risk | datum mismatch, flatness change after heat treatment or burrs on mating edges |
| Inspection focus | datum, hole/slot position, flatness |
Material Condition Reference
| Condition | What to expect | Watch out for | Surface notes |
|---|---|---|---|
| annealed | Use stable support and low-energy finishing. | Thermal surface effects can reduce fatigue resistance. | Specify recast and edge condition on fatigue and medical faces. |
| stress-relieved | Plan around stress relief and thin-wall movement. | Residual stress can distort delicate profiles. | Use trim passes and controlled post-processing on critical faces. |
Application and Material Context
Titanium Grade 2 is a commercially pure titanium grade with lower strength and higher ductility than alpha-beta Grade 5. In Sinker EDM for Precision Fixtures, limit aggressive energy on fatigue faces, control recast or contamination, and keep post-process cleanliness explicit. The material condition affects the acceptance route, but it is not itself a substitute for application-specific surface criteria.
Functional Surface-Integrity Requirements
For Sinker EDM on Titanium Grade 2 in Precision Fixtures, use separate acceptance statements: roughness for texture, recast for the resolidified layer, crack inspection where fatigue or brittleness matters, edge inspection for rollover or chipping, and corrosion or post-process verification where service requires it. Evaluate datum, hole/slot position, flatness from the correct datum.
Precision Fixtures Surface Checkpoints
- State the exact Titanium Grade 2 condition and identify the Sinker EDM features.
- Mark the functional faces and specify roughness, recast, edge, corrosion, fatigue, passivation, or post-process limits separately.
- Define how datum, hole/slot position, and flatness will be inspected before batch release.
Limits and Better Alternatives
Main Limit
A low Ra value cannot by itself approve the Titanium Grade 2 Sinker EDM surface for Precision Fixtures.
Consider Another Route When
Use Wire EDM for through profiles, CNC for open cavities with tool access, or grinding for simple flat precision surfaces.
Practical Next Step
Send the Precision Fixtures drawing with the Titanium Grade 2 condition, Sinker EDM features, functional faces, roughness target, recast or edge limits, quantity, and the method used to inspect datum, hole/slot position, flatness.
Practical Takeaway
For Precision Fixtures in Titanium Grade 2, Ra is only one part of Sinker EDM surface approval. Release the affected layer, material risk, post-process, and functional inspection separately.
Additional Project Information
Include application, destination and end-use notes together with the material, quantity and drawing requirements.
Project Details for Technical Review
Include application and end-use notes when they affect material, inspection, documentation, or export review.
- Process: Sinker EDM
- Material: Titanium Grade 2
- Application: Precision Fixtures
- Drawing or part sketch
- Material grade
- Thickness / part size
- Quantity
- Tolerance and critical dimensions
- Surface finish or inspection requirement
STEP/STP, DXF, DWG, PDF, IGS/IGES or ZIP.
Confidential drawing review. NDA support available on request.
Frequently Asked Questions
Is a low Ra value enough to approve this Sinker EDM surface?
No. Roughness, recast, edge damage, corrosion or fatigue risk, and post-processing are separate acceptance items. On Titanium Grade 2, the supplied condition and functional faces must also be identified before finish energy is selected.
Why use Sinker EDM for Precision Fixtures in Titanium Grade 2?
Use it when the feature is a blind cavity, rib, pocket, or internal form that a shaped electrode can reach from one side and the process supports repeatable datums, pin and bushing locations, wear surfaces and alignment features. The route is selected from the feature, not from the industry or material name alone.
How does the condition of Titanium Grade 2 affect surface planning?
The condition changes dimensional stability, recast behavior, residual stress, corrosion or fatigue response, and post-process needs. Thin sections can move and corrosion or medical surfaces need selective recast removal and cleanliness.
What should be inspected after machining?
Inspect roughness, recast, micro-cracks, edge condition, corrosion or fatigue risk, post-processing, datum, hole/slot position, and flatness separately on the functional faces. Add passivation or batch-repeatability checks where the drawing requires them.