Project Description
Introduction
4340 Alloy Steel is a premium heat-treatable, low-alloy steel containing nickel, chromium, and molybdenum. Known for its exceptional toughness, high strength in the heat-treated condition, and excellent fatigue resistance, it is a highly versatile material for critical structural components.
As a professional manufacturer holding API Q1 and ISO 9001 certifications, ShunFu Metal specializes in supplying 4340 Alloy Steel to the global oil and gas, drilling, and mining sectors. With a proven track record of exporting to over 50 countries and serving the world’s top 10 oilfield service companies, our factory guarantees that every batch meets the rigorous demands of extreme-duty applications.
Equivalent Grades
| Material No. | DIN | BS | ASTM | AFNOR | ISO | GOST | JIS |
|---|---|---|---|---|---|---|---|
| 1.6580 | 30CrNiMo8 | 823M30 | 4340 | 30CND8 | 31CrNiMo8 | 3KH3M3F | SNCM431 |
Applications
4340 Alloy Steel is utilized in high-stress environments where failure is not an option. ShunFu Metal supplies this grade for the following specific downstream products:
- Drill Collar Blanks & Downhole Tools (Oil & Gas / Drilling): Supplied as precision-machined hollow bars or heavy-wall tubes, utilizing our in-house BTA deep hole boring and CNC machining capabilities. For more details on our drill collar blanks and downhole tools, please see our dedicated category.
- Valve Body Forgings (Oil & Gas): Supplied as high-ratio forged round blocks, ensuring fine grain structure and internal soundness for high-pressure fluid control.
- Pump Shafts & Drive Shafts (Mining / Industrial): Supplied as turned and ground round bars, heat-treated in our API-calibrated furnaces to achieve optimal fatigue strength.
- High Voltage Bolts, Nuts & Pins (Heavy Engineering): Supplied as rolled or forged bar stock, ready for threading and final machining.
- Transmission Axles & Torsion Bars (Heavy Machinery): Supplied in the quenched and tempered condition, with mechanical properties verified by our accredited testing lab.
- Large-Mass Dies for Hot Stamping: Supplied as forged flat bars or blocks, customized to specific dimensional and hardness requirements.
Specifications & Standards
4340 Alloy Steel and its equivalents are covered under the following international standards:
- EN 10277: Bright steel products. Technical delivery conditions. Steels for quenching and tempering.
- EN 10083: Steels for quenching and tempering. Technical delivery conditions for alloy steels.
- EN 10269: Steels and nickel alloys for fasteners with specified elevated and/or low-temperature properties.
- EN 10263: Steel rod, bars, and wire for cold heading and cold extrusion.
- EN 10250: Open steel die forgings for general engineering purposes. Alloy special steels.
- ASTM A29: Standard Specification for Steel Bars, Carbon and Alloy, Hot-Wrought, General Requirements.
ShunFu Metal strictly organizes production according to the above standards and provides fully traceable Material Test Certificates (MTC) corresponding to your required specification.
Available Sizes & Delivery
ShunFu Metal offers highly flexible supply options for 4340 Alloy Steel, providing rolled and forged round bars, flat bars, and precision hollow bars/tubes. Our heavy-duty forging presses ensure a high forging ratio and fine grain structure, while our API-calibrated heat treatment furnaces and advanced machining center (equipped with BTA boring, CNC lathes, and long-distance gunhole drilling) deliver exact dimensions.
Delivery & Minimum Order Quantity (MOQ)
- Ready Stock: Common sizes are available from inventory; orders start at 1 piece with a delivery time of approximately 7 days.
- Custom Forged/Rolled: Standard MOQ is 3 tons, with a delivery time of approximately 30 days.
- Small Batch Special Melts: Our in-house induction furnaces accommodate customized 3–5 ton heats.
- Large Volume Orders: 30–60 ton Electric Arc Furnaces ensure rapid, stable delivery for major projects.
Chemical Composition
ShunFu Metal verifies every melt through in-house spectrometry before pouring, ensuring all elements strictly comply with specification. We can also fine-tune the chemical composition within standard limits to meet your specific performance requirements.
| Steel Grade | C (%) | Mn (%) | Si (%) | P (%) | S (%) | Cr (%) | Ni (%) | Mo (%) |
|---|---|---|---|---|---|---|---|---|
| 30CrNiMo8 | 0.26–0.34 | 0.50–0.80 | 0.40 max | 0.025 max | 0.035 max | 1.80–2.20 | 1.80–2.20 | 0.30–0.50 |
| 4340 | 0.38–0.43 | 0.60–0.80 | 0.15–0.35 | 0.035 max | 0.040 max | 0.70–0.90 | 1.65–2.00 | 0.20–0.30 |
| SNCM431 | 0.27–0.35 | 0.60–0.90 | 0.15–0.35 | 0.030 max | 0.030 max | 0.60–1.10 | 1.60–2.00 | 0.15–0.30 |
Bold values highlight the elemental variations between equivalent regional standards.
Melting & Processing
ShunFu Metal provides customized melting routes. Our standard process utilizes EAF + LF + VD for excellent purity. For stricter demands, we offer ESR or PESR, and for ultimate performance, VIM + VAR. Customers can negotiate the optimal metallurgical pathway with our engineering team to suit specific applications.
Mechanical Properties
ShunFu Metal conducts rigorous testing in our fully equipped metal laboratory. Before delivery, we issue mechanical property test reports from accredited facilities, with all data fully traceable to the specific heat and batch number. (T=20°C if not differently stated)
| Heat Treatment State | Diameter (mm) | Rm (MPa) | Rp0.2 (MPa) | Elongation A5 (%) | Impact Energy ISO-V (J) | Hardness (HB) |
|---|---|---|---|---|---|---|
| Soft Annealed | / | 844 min | / | / | / | 250 max |
| Isothermal Annealed | / | 615–815 | / | / | / | 183–242 |
| Quenched & Tempered | ≤ 16 | 880–1080 | 685 min | 16 min | 40 min | 289–347 |
| Quenched & Tempered | 16–40 | 930–1080 | 735 min | 16 min | 40 min | 275–318 |
| Quenched & Tempered | 40–100 | 880–1030 | 685 min | 17 min | 40 min | 261–303 |
| Quenched & Tempered | 100–250 | 785–935 | 635 min | 18 min | 35 min | 233–276 |
| Quenched & Tempered | 250–500 | 735–885 | 590 min | 16 min | 35 min | 218–262 |
Heat Treatment
ShunFu Metal’s heat treatment furnaces are strictly calibrated to API standards. This ensures precise temperature uniformity and process repeatability, guaranteeing that the 4340 Alloy Steel develops its maximum toughness and fatigue strength without localized weak points.
| Process | Temperature Range | Holding Time | Cooling Method |
|---|---|---|---|
| Annealing | 800 °C – 850 °C | Hold until uniform throughout section | Cool in furnace |
| Hardening | 830 °C – 860 °C | 10–15 mins per 25 mm of section | Quench in oil, water, or polymer |
| Stress Relieving | 600 °C – 650 °C | 1 hour per 25 mm of section | Cool in still air |
| Tempering | 450 °C – 660 °C | 1 hour per 25 mm of section | Cool in still air |
Note: Tempering should be avoided within the 250 °C – 450 °C range to prevent temper brittleness.
Surface Finish & Machining
Leveraging our in-house precision machining facility, ShunFu Metal supplies 4340 Alloy Steel in various surface conditions, including turned, ground, and milled finishes. We achieve strict dimensional tolerances and optimized surface roughness (Ra) through advanced CNC machining, BTA deep hole boring, and long-distance gunhole drilling. For fatigue-critical downhole components, we offer roller burnishing and shot peening to enhance surface integrity. By integrating these factory-direct machining capabilities, we deliver semi-finished or finished parts that significantly reduce your downstream processing time and costs.
Quality Assurance & Inspection
ShunFu Metal enforces rigorous quality control throughout production. Our API Q1 and ISO 9001 certified protocols mandate comprehensive testing, including ultrasonic testing (UT), chemical analysis, mechanical property verification, precise dimensional checks, and four-quadrant hardness testing. We also conduct thorough metallographic inspections to ensure structural integrity. This strict oversight guarantees that our 4340 Alloy Steel performs reliably in harsh oilfield and mining environments. We provide EN 10204 3.1 Material Test Certificates as standard, with 3.2 certification negotiable. Third-party inspections by SGS or TÜV are readily accommodated.
Packing & Shipping
With experience exporting to over 50 countries, ShunFu Metal ensures secure transit. Black surface products are tightly wire-bundled to prevent damage. Bright and precision-machined items receive multi-layer protective wrapping and anti-rust oil coating to guarantee rust-free ocean freight. We fully accommodate custom packaging and port-specific documentation requirements.
Frequently Asked Questions
Can ShunFu Metal supply 4340 Alloy Steel to API and ASTM specifications?
Yes. As an API Q1 certified manufacturer and a supplier to the world's top 10 oilfield service companies, ShunFu Metal strictly produces 4340 Alloy Steel to ASTM A29 and relevant API standards, ensuring full compliance for critical oil and gas applications.
What is the minimum order quantity for 4340 Alloy Steel products?
For ready stock, we accept orders starting from 1 piece. For custom forged or rolled requirements, our MOQ is typically 3 tons. We also utilize small induction furnaces for specialized 3–5 ton heats, giving you maximum purchasing flexibility.
How does ShunFu Metal handle the machinability and welding of 4340 steel?
4340 is readily machinable in the hardened and tempered condition, and our in-house CNC and BTA boring equipment handles it efficiently to provide you with semi-finished parts. Welding in the Q&T condition is not recommended; we advise welding in the annealed condition, followed by stress relieving in our API-calibrated furnaces to maintain mechanical integrity.
What delivery times can I expect for 4340 Alloy Steel orders?
Common ready-stock sizes ship in about 7 days. Custom forged/rolled orders typically deliver within 30 days. We also offer rapid delivery for small batch special melts and large-volume EAF orders.
