Hardening & Tempering
Bulk strength and hardness balanced to the material specification.
Availability confirmed per drawingFabrication & Secondary Processes
Heat Treatment for Precision Metal Parts
Hardness, wear resistance and dimensional stability planned around the material, drawing and complete manufacturing route.
OUJI reviews treatment, hardness method, test force, layer depth, metallography and post-treatment dimensions before confirming the plan.
- Hardness Method Review
- Case-Depth Verification
- Metallography Available
Treatment Selected From Material and Function
Not every alloy responds to every treatment. OUJI reviews the specified grade, starting condition, final properties and downstream operations before confirming the route.
Carburizing & Carbonitriding
A hard wear-resistant case with a different core condition.
Availability confirmed per drawingNitriding
Surface hardening reviewed around material grade, layer requirement and distortion risk.
Availability confirmed per drawingInduction Hardening
Localized hardening for selected surfaces and drawing-defined transition zones.
Availability confirmed per drawingAnnealing & Stress Relieving
Reduce hardness or internal stress before further machining or service.
Availability confirmed per drawingSolution Treatment & Aging
Reviewed for applicable aluminum, stainless and nickel-based alloy specifications.
Availability confirmed per drawingWhat We Review Before Heat Treatment
A hardness number alone is not enough. The correct treatment and verification plan depend on the complete part condition.
- Material grade, prior condition and mill certificate
- Required treatment and governing specification
- Target hardness scale, range and test locations
- Effective or total hardened-layer depth requirement
- Critical dimensions, datums and distortion sensitivity
- Grinding allowance and post-treatment machining plan
- Decarburization, oxidation and protected-area requirements
- Sampling quantity, test coupons and report requirements
- Treatment
- Confirmed from material grade and required function
- Hardness
- HRC, HRB, HBW, HV or HK as specified and technically suitable
- Test force
- Recorded with Vickers, Knoop and Brinell results
- Layer depth
- Effective or total depth verified to the agreed criterion
- Structure
- Metallographic preparation and examination available on request
- Dimensions
- Critical features checked after relevant processing
The Hardness Method Must Match the Part
Indenter, scale, test force, surface preparation, thickness and test position all influence whether a result is valid and representative.
Rockwell
HRC · HRB · Superficial RockwellFast macro-hardness verification where material, thickness, curvature and test location permit.
Scale and location must match the drawing or agreed inspection plan.Brinell
HBWUseful for bulk hardness assessment on suitable castings, forgings and coarser material structures.
Ball size, test force and specimen condition are selected for the material.Vickers
HV at specified test forceSuitable for smaller areas, cross-sections and hardness profiles from the surface toward the core.
The HV value is reported together with the applied test force.Knoop / Microhardness
HK or low-force HVUsed where the indentation must remain small, including thin layers and close hardness traverses.
Sample preparation and indent spacing are part of the measurement plan.
Case Depth Verified Point by Point
We determine hardened-layer depth with a controlled Vickers hardness traverse—not by appearance alone. A prepared cross-section is tested in stepped intervals, then the measured profile is reviewed against the drawing-defined hardness criterion.
Stepped traverse: test force, indent positions and distance from the surface are recorded with each HV result.
Representative Section
The test section is selected from the drawing and prepared to preserve a reliable path from the hardened surface toward the core.
Stepped Vickers Traverse
Vickers tester software guides a planned series of indents at controlled depth intervals from the surface toward the core.
Effective Case Depth
Each HV result is matched to its measured distance, and the specified hardness limit is used to determine the effective depth.
Experienced Result Review
Indent quality, spacing and borderline readings are reviewed by experienced personnel before the depth result is accepted and reported.
One Heat-Treat Plan Connected to the Drawing
- 01
Specification Review
Material, treatment, hardness, depth, critical dimensions and required records are confirmed.
- 02
Allowance & Route Planning
Pre-machining size, masking, test locations and post-treatment grinding are planned together.
- 03
Controlled Heat Treatment
The approved treatment is completed with part identification and process requirements communicated.
- 04
Hardness & Structure Verification
The specified scale, load, location, depth profile or metallographic checks are completed as required.
- 05
Final Dimensional Acceptance
Critical features are rechecked after treatment and any planned grinding or finishing operations.
Experience Shows Up in Risk Control
OUJI’s role is to connect heat-treatment decisions to machining allowance, datums, verification and final part acceptance.
Distortion
Plan machining allowance, datum strategy, support and final grinding before production starts.
Cracking
Review material, geometry, section changes and treatment sequence before release.
Soft Spots
Define valid test locations and use a hardness method suited to the material and surface.
Case-Depth Mismatch
Verify a cross-sectional hardness profile against the specified depth criterion.
Decarburization
Confirm surface protection and inspection requirements where the functional surface is affected.
Misleading Conversions
Prefer the specified test method; converted values are not treated as direct measurements.
Heat Treatment FAQs
Direct answers about hardness, depth, distortion, metallography and reports.
What information is needed for a heat-treatment review?
Send the material grade and starting condition, required treatment, governing standard, hardness scale and range, test locations, case-depth requirement, critical dimensions, quantity and required inspection records.
Which hardness test should be specified?
The correct method depends on material, hardness level, thickness, curvature, test location and whether bulk hardness or a small local region is being evaluated. Rockwell, Brinell, Vickers and Knoop results are not interchangeable without technical review.
Is a surface HRC reading enough for a case-hardened part?
Not always. A surface HRC result does not by itself show the hardness gradient or effective case depth. Case-hardened parts may require a polished cross-section and a Vickers or Knoop hardness traverse from the surface toward the core.
Can OUJI arrange metallographic analysis?
Yes, when required. The specimen location, section orientation, mounting, polishing, etching and examination objective must be defined so the result answers the drawing or failure-analysis question.
How is heat-treatment distortion managed?
Distortion risk is reviewed through material condition, geometry, section changes, machining allowance, datums, support and process sequence. Critical dimensions are checked after treatment, and grinding or other finishing is planned where needed.
What heat-treatment records can be supplied?
Depending on project requirements, available records may include process certificates, hardness results with scale and test force, case-depth profiles, metallographic images and post-treatment dimensional inspection reports.