AISI/SAE 4340 Carbon Steel Bar
AISI 4340 alloy steel is a heat treatable low alloy steel containing chromium, nickel and molybdenum. It has high toughness and high strength under heat treatment conditions.
Keywords:
AISI/SAE 4340 Carbon Steel Bar
Category:
Carbon Steel Bar
AISI/SAE 4340 Carbon Steel Bar Description
AISI 4340 alloy steel is a heat treatable low alloy steel containing chromium, nickel and molybdenum. It has high toughness and high strength under heat treatment conditions.
Product Parameters
Product Name | AISI/SAE 4340 Carbon Steel Bar | |||
Standard | EN/DIN/JIS/ASTM/BS/ASME/AISI, etc. | |||
Common Round Bar Specifications | 3.0-50.8 mm, Over 50.8-300mm | |||
Flat Steel Common Specifications | 6.35x12.7mm, 6.35x25.4mm, 12.7x25.4mm | |||
Hexagon Bar Common Specifications | AF5.8mm-17mm | |||
Square Bar Common Specifications | AF2mm-14mm, AF6.35mm, 9.5mm, 12.7mm, 15.98mm, 19.0mm, 25.4mm | |||
Length | 1-6meters, Size Accept Custom | |||
Diameter(mm) | Hot Rolling Round Bar | 25-600 | Cold Rolling Square Bar | 6-50.8 |
Hot Rolling Square Bar | 21-54 | Cold Rolling Hexagon Bar | 9.5-65 | |
Cold Rolling Round bar | 6-101.6 | Forged Rebar | 200-1000 | |
Surface Process | Bright, Polished, Black | |||
Other Services | Machining(cnc), Centerless Grinding(cg), Heat Treatment, Annealing, Pickling, Polishing, Rolling, Forging, Cutting, Bending, Small Machining, etc. | |||
Chemical Composition
Grade | Mn | S | C | P | Si | Cr | Ni |
AISI 4340 | 0.60-0.80 | 0.035 | 0.38-0.43 | 0.04 | 0.15-0.35 | 0.70-0.90 | 1.65-2.00 |
Mechanical Properties
Grade | Tensile Strength kg f/mm2 | Yield Strength kg f/mm2 | Elongation % | Hardness HB |
AISI 4340 | ≥ 100 | ≥90 | ≥ 16 | 293-352 |
Scope of Application
AISI 4340 alloy steel is mainly used for power transmission gears and shafts, aircraft landing gear and other structural parts.
Packing and delivery
The company has become a trustworthy partner of the international steel industry. After nearly two decades of unremitting efforts, our customer base now covers more than 110 countries and regions in Europe, the Middle East, South America, and Southeast Asia.

Contact Us
Factory workshop
As a leading steel supply chain enterprise, Jiangsu Yonggang Supply Chain Co., Ltd. has established a solid business network in domestic and international markets, relying on its strong resource integration capabilities. The company has a complete warehousing and logistics system covering major industrial areas, ensuring efficient product circulation. Through years of dedicated work, the company has accumulated rich industry experience, serving customers worldwide, including large-scale engineering projects and manufacturing enterprises. The company emphasizes sustainable development, significantly improving operational efficiency through optimized supply chain management, and providing customers with reliable and flexible solutions.
CUSTOMER VISIT
APPLICATION AREAS
The company's products are widely used in construction, machinery manufacturing, energy infrastructure, and other industries, meeting diverse domestic and international market demands. By integrating upstream and downstream resources, the company provides one-stop steel procurement and distribution services, aiming to become a core partner in the global steel supply chain.
CUSTOMER REVIEWS
Purchasing Manager
"We've been cooperating with Yonggang Steel for three years, and the product quality has always been consistently stable and reliable. Whether it's the tensile strength of the rebar or the dimensional accuracy of the profiles, they fully meet national standards, and some even surpass those of our competitors. Delivery times have never been delayed, especially for urgent orders. The sales team responds 24/7, and logistics are efficient, saving us considerable time and costs. I highly recommend them to any partner who needs high-quality steel!"
Technical Director
"We produce high-precision equipment, and we have high requirements for the material and processing performance of the steel." "Extremely high. Yonggang Steel's technical team customized steel plates with a special alloy ratio according to our needs, solving our long-standing problem of heat treatment deformation. Their professional service and rapid response make them a supplier we can trust long-term!"
Project Manager
"In the Yonggang high-speed rail project, Yonggang Steel provided full-service, one-stop service. From material selection and on-site technical guidance to after-sales testing, dedicated personnel were assigned to each step. Especially during the pandemic, they coordinated resources from multiple parties to ensure supply and maintain project progress. A company like this deserves to thrive!"
Plant Owner
"Even small-batch orders can enjoy VIP treatment! Yonggang Steel's sales team didn't treat our small orders carelessly; instead, they recommended a more material-saving cutting solution based on our processing techniques, helping us reduce material waste by 15%. Transparent pricing and flexible payment terms are incredibly friendly to SMEs!"
Export Trading Manager
"Export orders have strict requirements for material certification and packaging. Yonggang Steel's quality inspection reports are detailed and standardized, and the packaging uses rust-proof treatment and wooden pallets for reinforcement. There was no rust after three months of sea freight. Last year, we exported 3,000 tons of H-beams to Southeast Asia, and the customer had zero complaints during acceptance. This year, we've already increased our order to 8,000 tons!"
Need Assistance? We're Here To Help!
To request a quotation or locate your local distributor, please fill out the form below.lf you cannot find the product you need.
feel free to contact us and we will respond to you as soon as possible.
