ASTM A320 GRADE L43 – MTC
ASTM A320 Grade L43 Sample MTC Certificate
Access a comprehensive, professionally formatted Material Test Certificate according to EN 10204-2004: 3.1 for ASTM A320 Grade L43. Review the precise documentation verifying this premium AISI 4340 Nickel-Chromium-Molybdenum alloy steel, renowned for deep hardenability in heavy diameters and extraordinary low-temperature toughness.
What's Inside This A320 L43 MTC Certificate
This sample mill test certificate emphasizes the critical testing parameters required for ASTM A320 Grade L43—a high-strength, quenched and tempered alloy steel (AISI 4340) specifically selected for large-diameter fasteners operating in extreme low-temperature pressure environments.
- Full Traceability: Certified with TC No.: S156/26-XX and fully mapped to ASTM A320 heavy-diameter, low-temperature bolting specifications.
- Nickel-Enhanced Chemistry: Explicit verification of the 1.65 - 2.00% Nickel content. This critical addition enables uniform through-hardening and superior impact toughness even in fastener diameters up to 4 inches.
- Charpy V-Notch Impact Testing: Logs passing impact test energy values at the specified extreme low temperature of -150°F (-101°C), ensuring immunity to brittle fracture in cryogenic pipeline/vessel applications.
- Controlled Heat Treatment: Verification that the material was fully quenched and subsequently tempered at a minimum of 1100°F (593°C) to relieve residual stresses and maximize ductility.
- Mechanical Performance: Detailed logs of Tensile Strength (Min 860 MPa / 125 ksi), Yield Strength (Min 725 MPa / 105 ksi), Elongation (Min 16%), and Hardness (Max 321 HBW).
Live Preview: ASTM A320 Grade L43 MTC Data
Review the standard parameters and layout before downloading the full document.
TC Number
S156/26-XX
TC Date
10.03.20XX
Material Spec
ASTM A320 GRADE L43 (AISI 4340)
Bar Shape / Size
Round Bar / 3" (76.2 mm)
Dimensions / Item
Stud Bolt 3"-8UN x 20"
Quantity
50.00 NOS
Chemical Composition % (AISI 4340 Typical)
| C | Mn | P | S | Si | Ni | Cr | Mo |
|---|---|---|---|---|---|---|---|
| 0.40 | 0.75 | 0.015 | 0.010 | 0.25 | 1.85 | 0.82 | 0.25 |
| Min: 0.38 Max: 0.43 |
Min: 0.60 Max: 0.85 |
Max: 0.035 | Max: 0.040 | Min: 0.15 Max: 0.35 |
Min: 1.65 Max: 2.00 |
Min: 0.70 Max: 0.90 |
Min: 0.20 Max: 0.30 |
Mechanical & Impact Properties
| TENSILE STRENGTH (MPa) | YIELD STRENGTH 0.2% Offset (MPa) | % ELONGATION (GL-50mm) | HARDNESS (HBW) | IMPACT ENERGY @ -101°C (Joules) |
|---|---|---|---|---|
| 910.50 | 805.20 | 19.50 | 295, 298, 290 | 48, 50, 45 |
| Min: 860 (125 ksi) | Min: 725 (105 ksi) | Min: 16 | Max: 321 | Min: 27 (20 ft-lbf) @ -150°F |
Standard References & Compliance
Our MTC certificates comprehensively align with the demanding specifications of the low-temperature industrial sector. The test reports confirm exact compliance with ASME/ASTM A320 / A320M with respect to the specific heat and lot tested.
| Standard / Requirement | Confirmation on Certificate |
|---|---|
| Visual Inspection | 100% visual inspection carried out & found free from defects. |
| Charpy V-Notch Impact Test | Tested at -150°F (-101°C). Results meet minimum 20 ft-lbf requirement. |
| Safety Requirements | Material is free from radioactive contamination and mercury. |
| Dimensional Accuracy | All Dimensions are as per PO Specification / ASME B18.2.1 / ASME B18.31.2. |
Certification Details
We confirm that the above mentioned items were Manufactured, Sampled, Tested, and Inspected in accordance with the subjected Customer's Purchase Order and applicable Drawings, Material Specifications, Codes & Standards.
Documentation Standard
- EN 10204-2004: 3.1 Standard
- Free from radioactive contamination
- Certified ISO 9001: 2015 Company
Heat Treatments
- Quenched & Tempered
- Min Tempering Temp: 1100°F (593°C)
Testing Conditions
- Charpy Impact Test carried out at -150°F (-101°C)
- 100% visual inspection carried out
Technical FAQs — ASTM A320 Grade L43 MTC
What is the main difference between Grade L7 and Grade L43?
While both are high-strength alloy steels used for low-temperature service and require -150°F (-101°C) Charpy impact testing, their chemistry differs. Grade L7 is typically AISI 4140 (Chromium-Molybdenum), whereas Grade L43 is AISI 4340 (Nickel-Chromium-Molybdenum). The addition of approximately 1.8% Nickel in L43 drastically improves its hardenability and low-temperature toughness.
Why is Grade L43 preferred for large-diameter fasteners?
When quenching thick pieces of steel, the core cools slower than the surface, which can lead to a soft, weak center. The Nickel and Molybdenum content in Grade L43 (AISI 4340) allows the material to harden deeply and uniformly throughout its cross-section. Therefore, L43 is the standard choice for low-temperature fasteners larger than 2-1/2 inches in diameter (up to 4 inches) where standard L7 would fail to achieve the required core strength.
What does the -150°F Charpy V-Notch test guarantee?
Carbon and low-alloy steels undergo a "ductile-to-brittle transition" as temperatures drop, meaning they can shatter like glass if struck when freezing cold. The Charpy V-Notch impact test documented on this MTC proves that even at an extreme -150°F (-101°C), the L43 steel can still absorb at least 20 ft-lbf (27 Joules) of sudden energy without undergoing brittle fracture.