ASTM A194 GRADE 8NA NUTS
ASTM A194 Grade 8NA Nuts Sample MTC Certificate
Access a comprehensive, professionally formatted Material Test Certificate according to EN 10204-2004: 3.1 for Nitrogen-Strengthened Austenitic Stainless Steel Fasteners (ASTM A194 Grade 8NA / AISI 304N). Review verified chemical matrices, high yield strength validation, and specialized post-machining solution annealing logs optimized for severe structural loads and corrosive systems.
What's Inside This A194 Grade 8NA MTC Certificate
This sample mill test certificate mirrors the strict QA verification package standard for Class 1A nitrogen-bearing AISI 304N stainless steel nuts tracking specialized engineering environments shipped from our facility.
- Full Traceability: Issued under unique tracking index TC No.: S64/26-XX, fully correlated with verified mill heat identifiers to guarantee continuous product verification.
- Class 1A Solution Annealing: Explicit confirmation that the nuts have undergone mandatory solution annealing heat treatment after final tapping or cold forming, ensuring all residual stresses are fully eliminated.
- Nitrogen-Strengthened Chemistry: 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 ductility.
- Hardness & Thread Control: Hardness values tracked closely below the maximum standard limit of 233 HBW (95 HRB Rockwell max) to prevent localized galling while maintaining optimal load performance.
- Quality Compliance: 100% visual inspection carried out and verified free from defects and radioactive contamination.
Live Preview: ASTM A194 Grade 8NA MTC Data
Review the standard parameters and layout before downloading the full document.
TC Number
S64/26-XX
TC Date
19.06.20XX
Material Spec
ASTM A194 Grade 8NA (AISI 304N Class 1A)
Nut Profile / Size
Heavy Hex Nut / M24
Dimensions / Item
Heavy Hex Nut M24 x 3.0P
Quantity
550.00 NOS
Chemical Composition %
| C | Mn | P | S | Si | Cr | Ni | N | Fe |
|---|---|---|---|---|---|---|---|---|
| 0.058 | 1.68 | 0.032 | 0.010 | 0.48 | 18.45 | 8.30 | 0.125 | Rem |
| Max: 0.08 | Max: 2.00 | Max: 0.045 | Max: 0.030 | Max: 1.00 | 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) |
|---|---|---|
| 178 | 89 | 550 |
| Max: 233 | Max: 95 | Min: 515 (Heavy Hex Structural Layout) |
Standard References & Compliance
Our material quality records coordinate tightly with mechanical design protocols in chemical process networks and high-load civil structural joints. Thread layout evaluation passes with zero dimensional variances noted.
| 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 parameters verified strictly against standard ASME B18.2.2 criteria. |
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 Compliant
- Free from radioactive contamination
- Certified ISO 9001: 2015 Manufacturing System
Heat Treatments
- Class 1A Solution Annealed (Post-Machining)
- Liquid Quenched to achieve optimal carbide dispersion
Testing Conditions
- Hardness limits and proof load tracked at 25°C
- 100% thread path conformance verified
Technical FAQs — ASTM A194 Grade 8NA MTC Certificate
What metallurgical benefit does Nitrogen addition introduce in Grade 8NA nuts?
The "N" in Grade 8NA signifies the deliberate addition of Nitrogen (0.10% to 0.16%) to the austenitic crystal matrix (based on AISI 304N). Nitrogen acts as a highly effective solid-solution interstitial strengthener. It significantly increases the yield strength and tensile proof load capacity compared to standard Grade 8 elements, without causing structural embrittlement or lowering the material's general corrosion resistance.
What is the definitive significance of the "A" suffix in Grade 8NA?
The "A" indicates a Class 1A processing condition under ASTM A194 parameters. Standard Grade 8N fasteners can be formed from bars that were solution annealed prior to cold working. In contrast, Grade 8NA heavy hex nuts must undergo a mandatory solution annealing heat treatment after the final machining, drilling, and thread-tapping operations. This step eliminates all manufacturing stresses, bringing the hardness below critical limits and providing maximum protection against environmental stress corrosion cracking (SCC).
Why is there a strict maximum hardness ceiling of 233 HBW on the product certificate?
ASTM A194 strictly caps the hardness for Grade 8NA nuts at 233 Brinell (or 95 HRB on the Rockwell B scale). This requirement serves as a definitive quality check verifying that the post-machining solution annealing was completely successful. Keeping the material in a fully un-stressed, ductile condition prevents premature cracking and reduces the risk of thread galling during high-torque assembly preloads.