AISI4340 Alloy Steel Round Bar with Polished Surface and Diameter 20-300mm in Stock

Price Negotiable
Price: US $966-1,033 / Ton
MOQ: 1 Ton
Delivery Time: Negotiable
Product Description
ASME AISI4340 Alloy Steel Round Bar
Diameter 20 - 300mm in Stock Alloy Steel Rod
Product Specifications
ProductsAlloy Steel Round Bar
Diameter13 - 300mm
Length6m or custom cutting as request
Grade4340 Alloy Steel
Our ServiceCutting, polishing, packing, heat treatment
BrandBAOSTEEL, XINGCHENG, DSS, CHONGQING, XNSS, HLXT, etc.
StandardGB, ASTM, JIS, EN, DIN
Company TypeStorage company and process service
AISI 4340 steel (UNS G43400) is an ultra-high strength medium carbon low alloy steel, which combines deep hardenability, high ductility, toughness and strength, and has high fatigue resistance and creep resistance. It is not particularly affected by tempering and embrittlement, and exhibits good strength retention at high temperatures and is not easily softened. In thin sections, this steel is air-hardened. In practice, it is usually oil quenched.
Chemical Composition of 4340 Alloy Steel
AISI 4340 steel material chemical composition is listed in the following table based on cast analysis.
ASTMSteel Grade (UNS)CSiMnP (≤)S (≤)NiCrMoNotes
ASTM A29/A29M4340 alloy steel (UNS G43400)0.38-0.430.15-0.350.60-0.800.0350.041.65-2.000.70-0.900.20-0.30Steel Bars, Carbon and Alloy, Hot-Wrought
Additional applicable standards: ASTM A322, ASTM A519/A519M, ASTM A646/A646M
Mechanical Properties of 4340 Alloy Steel
SteelConditionTensile strength, MPa (ksi), ≥Yield strength, MPa (ksi), ≥Elongation in 50 mm (2 in.), ≥Reduction in area, %, ≥Hardness, HB, ≤
4340Normalized at 870 °C (1600 °F)1282 (186)862 (125)12.236.3363
4340Annealed at 810 °C (1490 °F)745 (108)470 (68)22.050.0217
4340Oil quenched from 800 °C (1475 °F) and tempered at 540 °C (1000 °F)1207 (175)1145 (166)14.245.9352
Applications of 4340 Alloy Steel
SAE AISI 4340 steel is typically used in applications with severe conditions and heavy parts requiring high strength. It can be widely used as billet, bar, forging, sheet, pipe and welding wire. AISI 4340 steel can also be produced as light plates and castings. Typical applications include:
  • Bolts, screws and other fasteners
  • Gears, pinions, shafts and similar mechanical components
  • Crankshafts and piston rods of engines
  • Landing gear and other key structural components of aircraft
International Equivalents of 4340 Alloy Steel
USEuropean UnionChinaJapanISO
AISI/SAE; ASTM A29/A29M; ASTM A322; ASTM A519/A519M; ASTM A646/A646MSAE AMS6414GB/T 3077 40CrNi2MoJIS G 4053 SNCM439
Company Information
Our company specializes in various types of round steel, including ling Steel, Xuan Steel, Benshan Steel, Tiangang, Shandong Luli steel, rongcheng steel, and serves as designated agent for major steel mills such as Professional, Handan, Laigang, Jiyuan steel. Monthly sales range from 40,000-60,000 tons of various steel types.
We maintain more than 4 warehouses for stock with approximately 30 product grades consistently available and over 800 sizes to ensure short delivery times for clients.
We operate a dedicated warehouse for steel round bar processing, including cutting, polishing, and heat treatment services.
Our sales network extends worldwide, with products widely used in various machinery, standard parts, automobiles, gears, forging, hardware tools and other industries.
Steel manufacturing facility and inventory
Popularly Used Steel Grades
We manufacture a comprehensive range of steel grades including EN series, C series, S series, SAE/AISI standards, BS970 standards, EN 10088-3 standards, ASTM standards, DIN standards, and GOST standards.
Products Show
Alloy steel round bars in warehouse storage Close-up view of alloy steel round bar surface Steel round bars organized in storage racks Quality inspection of alloy steel round bars

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Have questions about our products or want to discuss a custom order? Our team is ready to help you.

Company JIANGSU MITTEL STEEL INDUSTRIAL LIMITED
Location No.283-1, Youyi Middle Road, Xishan District, Wuxi City, Jiangsu Province
Contact Person Gao Ben

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