ASTM A194 GRADE 8LNA NUTS
ASTM A194 Grade 8LNA Nuts Sample MTC Certificate
Access a comprehensive, professionally formatted Material Test Certificate according to EN 10204-2004: 3.1 for Nitrogen-Strengthened, Low-Carbon Austenitic Stainless Steel Fasteners (ASTM A194 Grade 8LNA / AISI 304LN Class 1A). Review verified chemical boundaries, interstitial solution mechanisms, and specialized post-machining solution annealing logs engineered for reliable structural parameters.
What's Inside This A194 Grade 8LNA MTC Certificate
This sample mill test certificate mirrors the strict QA verification package standard for Class 1A post-machining solution-annealed nitrogen-bearing 304LN stainless steel heavy hex nuts shipped from our facility for critical structural and pressure-retaining allocations globally.
- Full Traceability: Issued under unique tracking index TC No.: S37/26-XX, fully correlated with verified mill heat lot identifiers to guarantee continuous product verification.
- Class 1A Solution Annealing: Explicit verification that components have undergone mandatory solution heat treatment after the final machining, tapping, and forming phases, thoroughly reversing cold-work strains and ensuring maximum microstructural stability.
- Nitrogen Interstitial Strengthening: Detailed chemical analysis showing the precise addition of Nitrogen (0.10-0.16%) paired with Chromium (18.00-20.00%) and Nickel (8.00-11.00%) to significantly elevate structural yield point limits without impairing impact toughness.
- Low Carbon Immunity: Breakdown verifying strict boundaries on Carbon content (0.030% max), mitigating chromium-rich carbide precipitation along grain interfaces during prolonged high-temperature exposure or standard field welding.
- Galling & Hardness Control: Hardness values tracked closely within the standard 126 to 300 HBW range (or 60 HRB Rockwell minimum) to preserve structural ductility and minimize localized thread galling parameters.
- Quality Compliance: 100% visual inspection carried out and verified free from defects and radioactive contamination.
Live Preview: ASTM A194 Grade 8LNA MTC Data
Review the standard parameters and layout before downloading the full document.
TC Number
S37/26-XX
TC Date
22.11.20XX
Material Spec
ASTM A194 Grade 8LNA (AISI 304LN Basis)
Nut Profile / Size
Heavy Hex Nut / M20
Dimensions / Item
Heavy Hex Nut M20 x 2.5P
Quantity
500.00 NOS
Chemical Composition %
| C | Mn | P | S | Si | Cr | Ni | N | Fe |
|---|---|---|---|---|---|---|---|---|
| 0.024 | 1.62 | 0.035 | 0.010 | 0.45 | 18.40 | 8.65 | 0.125 | Rem |
| Max: 0.030 | Max: 2.000 | Max: 0.045 | Max: 0.030 | Max: 1.000 | Min: 18.00 Max: 20.00 |
Min: 8.00 Max: 11.00 |
Min: 0.10 Max: 0.16 |
Rem |
Mechanical & Hardness Properties
| BRINELL HARDNESS (HBW) | ROCKWELL HARDNESS (HRB) | PROOF LOAD STRESS (MPa) |
|---|---|---|
| 160 | 84 | 530 |
| Min: 126 Max: 300 |
Min: 60 Max: 95 |
Min: 515 (Heavy Hex Style Framework) |
Standard References & Compliance
Our material quality records match structural limits required by cryogenic transport networks, fluid storage assemblies, and high-pressure chemical joints. The surfaces pass visual checks with zero anomalies found.
| Standard / Requirement | Confirmation on Certificate |
|---|---|
| Visual Inspection | 100% visual inspection carried out & found free from defects. |
| Safety Requirements | Material is certified free from radioactive contamination. |
| Weld Repairs | No weld repairs performed on finished stainless elements. |
| Dimensional Accuracy | All heavy hex sizing verified against ASME B18.2.2 requirements. |
Certification Details
We confirm that above mentioned Items was Manufactured, Sampled, Tested and Inspected in accordance with the subjected Customer's Purchase Order and as applicable Drawings, Material Specifications, Codes & Standards and the results of the items have been determined to meet the users' requirements.
Documentation Standard
- EN 10204-2004: 3.1 Compliance
- Free from radioactive contamination
- Certified ISO 9001: 2015 Operation
Heat Treatments
- Class 1A Solution Annealed (Post-Machining)
- Liquid Quenched to achieve optimal carbide solution
Testing Conditions
- Hardness limits and proof load tracked at 25°C
- 100% thread clearance testing performed
Technical FAQs — ASTM A194 Grade 8LNA MTC Certificate
What specific structural benefits does the inclusion of Nitrogen provide to Grade 8LNA nuts?
The "N" designator in Grade 8LNA highlights a deliberate interstitial addition of Nitrogen (0.10% to 0.16%) to the core austenitic matrix (based on AISI 304LN). Nitrogen functions as a highly effective solid-solution strengthener. It significantly elevates the baseline yield strength and proof load thresholds compared to non-nitrogen low-carbon variants, completely without sacrificing crucial sub-zero or cryogenic impact toughness metrics.
Why is a post-machining Class 1A solution annealing sequence mandatory for Grade 8LNA?
The "A" suffix establishes Class 1A tracking criteria under ASTM A194 guidelines. Standard Grade 8LN elements can be machined out of bars that were pre-annealed before cold drawing. Conversely, Grade 8LNA heavy hex nuts require a full solution anneal treatment after final machining, drilling, and thread-tapping operations are executed. This fully alleviates residual manufacturing strain and secures complete alloy dissolution, giving the fastener optimized structural protection against environmental stress corrosion cracking (SCC).
How does the low-carbon maximum rule preserve joint integrity in severe operational setups?
By capping Carbon at an ultra-low threshold of 0.030% max, Grade 8LNA successfully prevents sensitization—the precipitation of chromium-rich carbides along the grain interfaces during deep operational heat exposure or field welding operations. This low-carbon constraint leaves the Chromium fully free within the metal matrix to extend uniform atmospheric and general chemical protection.