ASTM A194 GRADE 8MLNA NUTS
ASTM A194 Grade 8MLNA Nuts Sample MTC Certificate
Access a comprehensive, professionally formatted Material Test Certificate according to EN 10204-2004: 3.1 for Nitrogen-Strengthened Molybdenum Austenitic Stainless Steel Fasteners (ASTM A194 Grade 8MLNA / AISI 316LN). Review verified low-carbon chemistry arrays, high yield criteria, and custom post-machining Class 1A solution annealing logs engineered for severe corrosion and aerospace applications.
What's Inside This A194 Grade 8MLNA MTC Certificate
This sample mill test certificate mirrors the high-level QA verification package required for Class 1A solution-annealed nitrogen-bearing 316LN stainless steel heavy hex nuts shipped from our facility for critical marine and chemical plant deployments.
- Full Traceability: Issued under unique tracking index TC No.: S75/26-XX, fully correlated with verified mill heat 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.
- Low-Carbon Nitrogen Chemistry: Detailed chemical analysis showing the precise addition of Nitrogen (0.10-0.16%) combined with ultra-low Carbon (0.030% max) to provide increased structural strength while totally preventing intergranular chromium carbide precipitation.
- Controlled Structural Hardness: Reports verified mechanical testing limits maintaining Brinell parameters safely within the standard 126 to 192 HBW range (or 60 to 90 HRB Rockwell B scale) to isolate threads from torque-induced structural galling.
- Quality Compliance: 100% visual inspection carried out and verified free from defects and radioactive contamination.
Live Preview: ASTM A194 Grade 8MLNA MTC Data
Review the standard parameters and layout before downloading the full document.
TC Number
S75/26-XX
TC Date
28.10.20XX
Material Spec
ASTM A194 Grade 8MLNA (AISI 316LN Class 1A)
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 | Mo | N | Fe |
|---|---|---|---|---|---|---|---|---|---|
| 0.022 | 1.55 | 0.032 | 0.010 | 0.45 | 17.20 | 11.40 | 2.35 | 0.125 | Rem |
| Max: 0.030 | Max: 2.000 | Max: 0.045 | Max: 0.030 | Max: 1.000 | Min: 16.00 Max: 18.00 |
Min: 10.00 Max: 13.00 |
Min: 2.00 Max: 3.00 |
Min: 0.10 Max: 0.16 |
Rem |
Mechanical & Hardness Properties
| BRINELL HARDNESS (HBW) | ROCKWELL HARDNESS (HRB) | PROOF LOAD STRESS (MPa) |
|---|---|---|
| 158 | 83 | 530 |
| Min: 126 Max: 192 |
Min: 60 Max: 90 |
Min: 515 (Heavy Hex Style Framework) |
Standard References & Compliance
Our material quality records match structural limits required by marine engineering, saltwater handling equipment, and high-purity processing systems. 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)
- Rapidly Quenched to achieve complete carbide solution
Testing Conditions
- Hardness limits and proof load tracked at 25°C
- 100% thread clearance testing performed
Technical FAQs — ASTM A194 Grade 8MLNA MTC Certificate
What specific structural benefits does the inclusion of Nitrogen provide to Grade 8MLNA nuts?
The "N" designator in Grade 8MLNA highlights a deliberate addition of Nitrogen (0.10% to 0.16%) to the core austenitic balance (based on AISI 316LN). Nitrogen acts as a robust interstitial solid-solution strengthener, which substantially raises the minimum yield strength and proof load rating compared to non-nitrogen grades like 8MA, while entirely retaining excellent low-temperature impact ductility.
Why is a post-machining Class 1A solution annealing sequence mandatory for Grade 8MLNA?
The "A" suffix establishes Class 1A tracking criteria under ASTM A194 guidelines. Standard Grade 8MLN elements can be machined out of bars that were pre-annealed before cold drawing. Conversely, Grade 8MLNA 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 harsh marine boundaries?
By capping Carbon at an ultra-low threshold of 0.030% max, Grade 8MLNA successfully prevents sensitization—the precipitation of chromium-rich carbides along the grain interfaces during deep operational heat exposure or welding operations. This low-carbon constraint leaves the Chromium fully free within the metal matrix to combine with Molybdenum (2.00-3.00%), ensuring outstanding localized pitting and crevice resistance in chloride-dense environments.