ASTM A194 GRADE 8CLNCuBA NUTS
ASTM A194 Grade 8CLNCuBA Nuts Sample MTC Certificate
Access a comprehensive, professionally formatted Material Test Certificate according to EN 10204-2004: 3.1 for Advanced Stabilized Austenitic Stainless Steel Fasteners (ASTM A194 Grade 8CLNCuBA / UNS S34752). Verify highly complex chemical matrices, supreme resistance profiles to polythionic acid stress corrosion cracking, and specialized post-machining Class 1A solution heat treatments.
What's Inside This A194 Grade 8CLNCuBA MTC Certificate
This sample mill test certificate mirrors the thorough quality verification package standard for Class 1A post-machining solution-annealed, copper-and-columbium-modified premium stainless steel heavy hex nuts shipped from our facility to satisfy severe high-temperature petroleum and refinery infrastructure setups.
- Full Traceability: Issued under unique tracking index TC No.: S35/26-XX, fully correlated with verified mill heat numbers to guarantee continuous material verification.
- Class 1A Solution Annealing: Explicit verification confirming that components have undergone a mandatory solution annealing heat treatment after final machining or thread-tapping operations, successfully relieving micro-stress variables.
- Advanced Multi-Alloy Chemistry: Detailed analysis showing precise distributions of Chromium (17.00-19.00%), Nickel (10.00-13.00%), Copper (2.50-3.50%), Niobium/Columbium (0.20-0.50%), Nitrogen (0.06-0.12%), and controlled Boron (0.001-0.005%) for exceptional material longevity.
- Galling & Crack Defiance: The copper and nitrogen additions dramatically suppress stress relaxation cracking and polythionic acid stress corrosion cracking (PTA-SCC) without needing PWHT (post-weld heat treatment).
- Mechanical Performance Boundaries: Core reporting verifies compliance with standard proof stresses and holds hardness under the strict maximum threshold of 223 HBW (or 96 HRB) to rule out brittleness.
- Quality Compliance: 100% visual inspection carried out and verified free from defects and radioactive contamination.
Live Preview: ASTM A194 Grade 8CLNCuBA MTC Data
Review the standard parameters and layout before downloading the full document.
TC Number
S35/26-XX
TC Date
14.11.20XX
Material Spec
ASTM A194 Grade 8CLNCuBA (UNS S34752)
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 | Cu | Nb | N | B |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 0.015 | 1.45 | 0.028 | 0.005 | 0.42 | 17.80 | 11.20 | 0.55 | 2.95 | 0.32 | 0.095 | 0.003 |
| Min: 0.005 Max: 0.020 |
Max: 2.00 | Max: 0.035 | Max: 0.010 | Max: 0.60 | Min: 17.00 Max: 19.00 |
Min: 10.00 Max: 13.00 |
Min: 0.20 Max: 1.20 |
Min: 2.50 Max: 3.50 |
Min: 0.20 Max: 0.50 |
Min: 0.06 Max: 0.12 |
Min: 0.001 Max: 0.005 |
Mechanical & Hardness Properties
| BRINELL HARDNESS (HBW) | ROCKWELL HARDNESS (HRB) | PROOF LOAD STRESS (MPa) |
|---|---|---|
| 175 | 88 | 530 |
| Max: 223 | Max: 96 | Min: 515 (Heavy Hex Structural Standard) |
Standard References & Compliance
Our material quality records match structural boundaries required by advanced petroleum refining, high-temperature furnace tubes, and heavy chemical industrial installations. The surfaces pass visual checks with zero defects 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 sizing verified against standard 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 Carbide Solution Treated (Post-Machining)
- Rapidly liquid quenched to secure fully uniform alloy phase
Testing Conditions
- Hardness limits and proof load tracked at 25°C
- 100% thread clearance testing performed
Technical FAQs — ASTM A194 Grade 8CLNCuBA Nuts
What specific chemical structure distinguishes Grade 8CLNCuBA from regular stainless steel?
ASTM A194 Grade 8CLNCuBA heavy hex nuts are mapped to the highly advanced UNS S34752 composition template (often utilized in proprietary steel formulas like NEXAGE™ 347AlPha). It features a precisely controlled, low-carbon chemistry matrix optimized with deliberate additions of Copper (2.50–3.50%), Molybdenum (0.20–1.20%), Niobium/Columbium stabilization (0.20–0.50%), Nitrogen, and tiny amounts of Boron. This creates peerless resistance to stress relaxation cracking and polythionic acid environments.
What is the definitive purpose of the "A" suffix within the Grade 8CLNCuBA parameters?
The final "A" designator stands for a mandatory Class 1A carbide-solution heat treatment executed *after* the nuts have been completely machined, forged, and thread-tapped. Due to the multi-alloy complexity of UNS S34752, cold machining strains could lead to localized structural vulnerability. Post-tapping solution annealing re-dissolves any precipitate clusters and yields an ultra-ductile, stress-relieved matrix with a maximum hardness safety limit capped at 223 HBW.
How does this grade eliminate the need for post-weld heat treatment (PWHT)?
Thanks to the joint stabilization actions of Niobium (Columbium) combined with Nitrogen and Copper, the alloy strongly resists sensitization during thermal cycles. Carbon is successfully bound up by Niobium, leaving Chromium free to protect grain interfaces. Consequently, fasteners and associated components can tolerate high heat and welding environments without incurring a risk of intergranular strain tracking, eliminating the need for expensive field PWHT operations.