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AISI/SAE 4340 Alloy Steel Bar

AISI 4340 carbon steel bar is made of a heat treatable low alloy steel containing chromium, nickel and molybdenum. It has high toughness and high strength under heat treatment conditions.

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AISI/SAE 4340 Alloy Steel Bar Description

AISI 4340 is a commonly used alloy steel with high strength, high toughness, good wear resistance and corrosion resistance. Its moderate carbon content gives it good machinability and weldability. In addition, it also contains appropriate amounts of chromium, nickel and other elements, which further improves its performance. At the same time, its toughness and ductility are also quite good, and it can maintain good performance even in both high or low temperature environments. Due to the excellent physical and mechanical properties of 4340 steel, 4340 steel bars are also widely used in equipment manufacturing in corrosive environments such as petroleum, chemical industry, and ships.

Product Parameters

Product Name	AISI/SAE 4340 Alloy 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.

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FAQ

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Q：

How do you guarantee product quality?

A：

Our factory operates under strict QA/QC standards. Every product is inspected during production and before shipment to ensure it meets agreed quality specifications. We can provide mill test certificates and accept thirdparty inspections upon request.

Q：

What certifications do you have?

A：

Our products comply with international standards including ASTM, ASME, DIN, and EN. We also hold quality management certifications and can provide relevant documentation upon request.

Q：

Can I get samples before ordering?

A：

Yes. We can provide free samples for your evaluation. Shipping costs are typically borne by the customer. Please contact our sales team to arrange sample delivery.

Q：

What is your minimum order quantity (MOQ)?

A：

MOQ varies by product type and specification. For certain items, trial orders may be considered. Please contact us with your specific requirements for a confirmed MOQ.

Q：

What payment terms do you accept?

A：

We commonly accept T/T (30% deposit in advance, 70% balance before shipment) and L/C. Other payment terms may be negotiated depending on order value and cooperation conditions.

Q：

Do you offer discounts for large orders?

A：

Yes. We have strong capabilities for largescale project supply and offer favorable pricing for bulk orders. Our 100,000ton stock capacity allows us to provide competitive rates for volume purchases.

Q：

What is your typical lead time?

A：

For stocked products, we can deliver to the loading port within 3–7 days after receiving the deposit. For production orders, lead time is typically 15–30 days after order confirmation, depending on product type and quantity.

Q：

What shipping terms do you support?

A：

We support EXW, FOB, CIF, CFR, DDU, and other common trade terms. Shipping can be arranged by sea, air, or courier based on your requirements.

Q：

How do you package the products?

A：

We use standard export packaging suitable for sea freight. For fragile or highsurfacefinish products such as stainless steel, we apply strict protective packaging to prevent scratches and damage during transit. Custom packaging is also available upon request.

Q：

How can I become your agent?

A：

We are actively recruiting regional agents worldwide. If you are interested, please contact us with your background, market coverage, and target regions. We offer competitive agent policies and full support for your local market development.

Q：

Do you accept bulk procurement orders?

A：

Yes. Bulk procurement is one of our core business models. With over 100,000 tons of stock and a robust supply chain, we are wellequipped to handle largevolume orders for overseas projects, manufacturers, and trading companies.

Q：

Do you provide aftersales service?

A：

Yes. Our professional service team is available to address any questions regarding product quality, delivery, or usage. We are committed to providing ongoing support throughout our partnership.

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