Project Description
AISI 4161 Steel Round Bar
AISI 4161 is a premium high-carbon chromium-molybdenum alloy steel renowned for its exceptional tensile strength, high hardness, and superior wear resistance. The strategic addition of chromium and molybdenum significantly enhances its hardenability and impact resistance, making it an ideal choice for high-stress, heavy-duty components.
As an API Q1 and ISO 9001 certified manufacturer, ShunFu Metal specializes in supplying AISI 4161 Steel Round Bar to the global oil and gas and mining sectors. Trusted by the world’s top 10 oilfield service companies, we leverage our extensive export experience and advanced production capabilities to deliver this grade with uncompromising material integrity for your most critical applications.
Equivalent Grades
| Standard | Grade / Designation |
|---|---|
| UNS | G41610 |
| SAE / AISI | 4161 |
| ASTM | 4161 |
Applications
- Drill Collar Blanks (Oil & Gas & Drilling): Supplied by ShunFu Metal as precision-machined hollow bars or heavy-wall forged round bars, heat-treated in our API-calibrated furnaces to exact specifications for maximum fatigue resistance in harsh downhole environments.
- High-Strength Shafts and Gears (Mining & Heavy Machinery): Delivered as forged round steel bars, fully quenched and tempered by our in-house metallurgical team to ensure uniform sorbite structures and exceptional wear resistance under heavy loads.
- Downhole Tool Components (Oil & Gas): Provided as custom-machined parts utilizing our advanced CNC lathe and milling capabilities, ensuring the tight tolerances required by top-tier oilfield service companies.
- Rock Drill Steel Components (Mining): Supplied as rolled or forged bars with optimized grain structures, ready for final manufacturing into high-impact rock drilling tools, backed by our rigorous quality control.
Specifications & Standards
ShunFu Metal strictly organizes production according to the following recognized standards. Our fully equipped metallurgical laboratory can issue comprehensive material test certificates corresponding to these standards based on your specific project requirements.
Available Sizes & Delivery
ShunFu Metal offers a highly flexible supply of AISI 4161 Steel Round Bar, flats, and custom hollow bars. We provide hot-rolled bars from 20mm to 150mm and forged round bars up to 800mm. Our advanced forging capabilities ensure a high forging ratio and refined grain size. Combined with our API-compliant, regularly calibrated heat treatment furnaces and precision machining equipment—including BTA deep hole boring, CNC lathes, and long-distance gunhole drilling—we deliver exact dimensions.
For common grades, we maintain ready stock with a minimum order quantity (MOQ) of a single piece and a 7-day delivery. Custom forged or rolled materials typically require a 3-ton MOQ with a 30-day lead time. For specialized small batches, our induction furnaces accommodate 3–5 ton melts, while our 30–60 ton Electric Arc Furnaces guarantee rapid delivery for large-scale orders.
Chemical Composition
| Element | Content (%) |
|---|---|
| Carbon (C) | 0.56 – 0.64 |
| Manganese (Mn) | 0.75 – 1.00 |
| Phosphorus (P) | ≤0.035 |
| Sulfur (S) | ≤0.040 |
| Silicon (Si) | 0.15 – 0.35 |
| Chromium (Cr) | 0.70 – 0.90 |
| Molybdenum (Mo) | 0.25 – 0.35 |
ShunFu Metal meticulously verifies the chemical makeup of every heat through advanced in-house spectrometry prior to pouring, ensuring all element levels strictly comply with ASTM and SAE specifications while allowing our engineers to fine-tune the composition based on your specific performance requirements.
Melting & Processing
ShunFu Metal offers tailored melting routes: standard EAF + LF + VD for excellent purity, ESR or PESR for higher demands, and VIM + VAR for the most critical applications. Customers can collaborate with our metallurgical engineers to select the optimal melting process for their specific operational requirements.
Mechanical Properties
Typical values for quenched & tempered condition.
| Property | Value |
|---|---|
| Tensile Strength (Rm) | ≥1030 MPa |
| Yield Strength (Rp0.2) | ≥860 MPa |
| Elongation (A5) | ≥12% |
| Hardness | 30 – 36 HRC |
Prior to delivery, ShunFu Metal provides comprehensive mechanical property test reports issued by our fully equipped, accredited laboratory, with all data strictly traceable to the specific heat and production batch.
Heat Treatment
| Treatment | Temperature Range | Cooling Method |
|---|---|---|
| Normalizing | 870°C – 900°C | Air Cool |
| Annealing | 815°C – 845°C | Furnace Cool |
| Quenching | 830°C – 860°C | Oil Quench |
| Tempering | 540°C – 680°C | Air Cool |
ShunFu Metal’s heat treatment facilities strictly adhere to API standards with routine calibration, guaranteeing exceptional temperature uniformity and process repeatability. This ensures every AISI 4161 product achieves the exact tempered martensite structure required for your critical applications.
Surface Finish & Machining
Leveraging our state-of-the-art in-house machining facility, ShunFu Metal provides AISI 4161 products in various surface conditions, from rough-turned to precision-ground. Our capabilities include CNC turning and milling, BTA deep hole boring, roller burnishing, and shot peening. We can achieve exacting surface roughness values down to Ra 0.4 μm and tight dimensional tolerances tailored to your drawings. By integrating these precision machining services directly at our factory, we eliminate third-party delays and ensure your components arrive installation-ready with flawless surface integrity.
Quality Assurance & Inspection
ShunFu Metal implements rigorous pre-, in-, and post-production quality controls. Our comprehensive inspection protocol includes 100% Ultrasonic Testing (UT), precise dimensional checks, chemical and mechanical analysis, metallographic examination, and strict four-quadrant hardness testing. Operating under API Q1 and ISO 9001 certifications guarantees that every AISI 4161 steel round bar meets the highest oilfield integrity standards.
We supply standard EN 10204 3.1 certificates, with 3.2 certification available upon request, and readily accommodate third-party inspections from agencies like SGS or TÜV to ensure absolute peace of mind.
Packing & Shipping
With experience exporting to over 50 countries, ShunFu Metal ensures secure global delivery. Black-surface materials are tightly bound with steel wire, while precision-machined products receive multi-layer protective packaging and premium anti-rust oil coating to guarantee flawless, corrosion-free arrival during long-haul ocean freight. We fully accommodate custom destination-port documentation.
Frequently Asked Questions
Can ShunFu Metal supply AISI 4161 Steel Round Bar to specific API or ASTM specifications?
Yes, our technical team of 22 metallurgy and materials engineers ensures that all AISI 4161 products strictly conform to ASTM A29, ASTM A322, and relevant API standards. Our fully equipped metal laboratory verifies all specifications and issues fully traceable certification before shipment.
What is the minimum order quantity for AISI 4161 hollow bars or custom forgings?
For custom forged or rolled AISI 4161, our MOQ is typically 3 tons with a 30-day lead time. However, utilizing our small induction furnaces, we can easily accommodate specialized trial batches starting from 3–5 tons to support your R&D or specialized project needs.
How does ShunFu Metal ensure the straightness and internal quality of long AISI 4161 drilling components?
We utilize advanced BTA boring and long-distance gunhole drilling for internal precision, followed by rigorous 100% Ultrasonic Testing (UT) and straightness checks. Our API-calibrated heat treatment processes further prevent distortion, ensuring top-tier reliability for demanding oilfield applications.
What is the typical delivery time for AISI 4161 round bars?
For common grades in ready stock, delivery can be as fast as 7 days with a single-piece minimum order. Custom forged or rolled materials typically require a 30-day lead time. Large-volume orders benefit from our 30–60 ton Electric Arc Furnaces to accelerate production schedules.