4140 Alloy Steel Flat Bar

Flat alloy bars are available in a diverse selection of grades and finishes processed to meet your exact requirements. Whether you require full-length alloy bars or small, cut pieces, we have the product on hand and processing capabilities to turn around

Product Introduction

◆ Standards

Equivalent material of 4140 flat bar
GB/T 3077-2015
EN 10083-3:2006
ASTM A29/A29M-2012
JIS G 4053-2008

◆ Properties

Chemical properties of 4140 alloy steel flat bar


Recommended 4140 Flat Bar Heat Treatment Regime
Sample blank size/mmQuenchingTemper
heating temperature / ℃
coolantheating temperature / ℃coolant
water, oil

Mechanical properties of 4140 steel flat bar
Tensile Strength
Lower Yield Strength
Elongation After Break
Rate of Reduction in Area
Impact absorption energy

Brinell Hardness


Note: Available as annealed or high temperature tempered.


4140 alloy steel flat bar is an cold drawn annealed steel of relatively high hardenability with its chromium content provides good hardness penetration, and the molybdenum imparts uniformity of hardness and high strength. 4140 alloy steel flat bar responds well to heat-treatment and is relatively easy to machine in the annealed condition. 4140 steel flat bar has good strength and wear resistance, excellent toughness, coupled with good ductility, and the ability to resist stress at elevated temperatures.

4140 flat bar is used to manufacture forgings with higher strength and larger quenched and tempered sections. Such as large gears for locomotive traction, supercharger transmission gears, rear axles, highly loaded connecting rods and spring clips. 4140 flat steel can also be used for oil deep well drill pipe joints and fishing tools below 2000m.

Purchasing Information

Product name

4140 Alloy Steel Flat Bar
Hot Rolled, Cold Finished
Thicknesses0.109" thru 4"
Widthsup to 14.625"
GB/T 3077-2015, ASTM A29/A29M-2012, JIS G 4053-2008
WorkabilityModerate to Weld, Cut and Machine.
Available Stock Sizes2ft, 4ft, 6ft, 8ft, 12ft or Cut to Size
MOQ1 ton
Supply Ability5000 tons / month
Lead Time
10-15 working days after the receipt of 30% deposit
Payment Terms
30%T/T Advance + 70% Balance
Price TermsFOB, CFR, CIF, EXW
PackingStandard sea-worthy package or as required
*If you do not find what you are looking for, please call us now. If you have found it, we are happy to answer any questions or concerns you may have about flat bar grades and assist you through the purchasing process.


Q:Can you send samples?

A:Sample can be for free,freight cost collect.

Q:What product information do I need to provide?

A:Steel grade/thickness/width/quantity,these will decide the price.

Q:About product prices?

A:Prices vary from period to period due to cyclical changes in the price of raw materials.

Q:What are the certifications for your products?

A:We have ISO 9001,CE,SGS,BV and other certifications.

Q:How about the delivery time?

A:Regularly the delivery time around 10-15 days,customized one will inform the delivery time ahead.

Q:Does the product have quality inspection before loading?

A:All the products are strictly tested before packaging,also can inspect by third party inspection.

Q:How to pack the products?

A:Standard export package with waterproof film and wooden pallet.It can effectively protect products from corrosion.

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