Product Description
1. AISI 4140 Steel Introduction
AISI 4140 is defined as a low alloy steel which has 1% Cr-Mo as strengthening alloy elements.Compared with AISI 4130, it has a higher carbon content with good balance of strength, toughness ,abrasion and impact resistance and heat treatment capabilities,but poor in weldability characteristics.AISI 4140 is generally supplied in quenched and tempered condition with hardness 28-32HRC
2. AISI 4140 Steel Equivalent
| Country | China | Japan | Germany | USA | British |
| Standard | GB/T 3077 | JIS G4105 | DIN (W-Nr.) EN 10250 |
AISI/ASTM ASTM A29 |
BS 970 |
| Grade | 42CrMo | SCM440 | 42crmo4/1.7225 | 4140 | EN19/709M40 |
3. AISI 4140 Steel Chemical Composition
| Grade | C | Si | Mn | P | S | Cr | Mo | Ni |
| 42CrMo | 0.38-0.45 | 0.17-0.37 | 0.5-0.80 | ≤0.035 | ≤0.035 | 0.9-1.2 | 0.15-0.25 | - |
| SCM440 | 0.38-0.43 | 0.15-0.35 | 0.6-0.85 | ≤0.035 | ≤0.04 | 0.9-1.2 | 0.15-0.30 | - |
| 42crmo4/1.7225 | 0.38-0.45 | ≤ 0.4 | 0.6-0.9 | ≤0.025 | ≤0.035 | 0.9-1.2 | 0.15-0.30 | - |
| 4140 | 0.38-0.43 | 0.15-0.35 | 0.75-1.00 | ≤0.035 | ≤0.04 | 0.8-1.1 | 0.15-0.25 | - |
| EN19/709M40 | 0.35-0.45 | 0.15-0.35 | 0.5-0.80 | ≤0.035 | ≤0.035 | 0.9-1.5 | 0.2-0.40 | - |
4. AISI 4140 Steel Mechanical Properties(for guidance only)
| Grade | Tensile strength σb(MPa) |
Yield strength σs (MPa) |
Elongation δ5 (%) |
Reduction ψ (%) |
Impact Value Akv (J) |
Hardness |
| 4140 | ≥1080 | ≥930 | ≥12 | ≥45 | ≥63 | 28-32HRC |
5. AISI 4140 Steel Overviews
| Size | Round | Dia 6-1200mm |
| Plate/Flat/Block | Thickness 6mm-500mm |
|
| Width 20mm-1000mm |
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| Heat treatment | Normalized ; Annealed ; Quenched ; Tempered | |
| Surface condition | Black; Peeled; Polished; Machined; Grinded; Turned; Milled | |
| Delivery condition | Forged; Hot rolled; Cold drawn | |
| Test | Tensile strength, Yield strength, elongation, area of reduction, impact value, hardness, grain size, ultrasonic test, US inspection, magnetic particle testing, etc. | |
| Payment terms | T/T;L/C;/Money gram/ Paypal | |
| Trade terms | FOB; CIF; C&F; etc.. | |
| Delivery time | 30-45 days | |
| Application | AISI 4140 steel finds many applications as forgings for the aerospace,oil and gas,automotive, agricultural and defense industries etc. Typical applications for 4140 steel uses include:forged gears,spindles,fixtures,jigs,collars,Axles,conveyor parts,crow bars,logging parts,shafts,sprockets,studs,pinions,pump shafts, rams, and ring gears etc |
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6. Delivery Condition
For hot forged or hot rolled bar, usually the delivery condition is hot forged or rolled, annealed, rough turned.
For hot forged plate, usually the delivery condition is hot forged, annealed, milled surface.
For hot rolled plate, usually the delivery condition is hot rolled, annealed, black surface
Main Products
| Alloy Steel | 4140,4142,42CrMo4,1.7225,SCM440,4130,SCM430,25CrMo4,1.7218,34CrNiMo6, 1.6582,4340,SNCM439,36CrNiMo4,1.6511,SACN645,1340,SMn438,SNC236, |
| Tool Steel | H13,1.2344,SKD61,D2,SKD11,1.2379,1.2510,01,SKS3,95MnWCr5,D3,SKD1,1.2419, SKS31,H21,SKD5,1.2581,P20,35CrMo7,1.2738,1.2316,M2 |
| Bearing Steel | GCr15,52100,SUJ1,SUJ2,100Cr6,1.2067,55C,8620,4320,9310,440C,M50 |
| Spring Steel | 9260,SUP6,SUP7,1.7108,54SiCr6,1.7102,5155,SUP9,1.7176,5160,1.7177,6150, SUP10,51CrV4,1.8159 |
| Stainless Steel | 321,sus321,1.4541,304,SUS304,1.4301,410,SUS410,1.4006,420,1.4021,1.4028, 434,1.4113,316L,SUS316L,1.4435,630,1.4542,431,1.4057 |


1.What alloy is structural steel?
Common Alloys for Structural Steel
Some of the most common include: Cold-rolled ASTM-A1008: This is a low-carbon steel that can be created in multiple different formed shapes, such as channel and angle. This makes it excellent for many foundational structural applications.
2.Which is better, SS or MS?
Fabrication. As chrome is a hard alloy, stainless steels are much more impact resistant compared to mild steel and (although relatively easy to fabricate) are not as easy to fabricate as mild steel. Mild steel is much more malleable compared to stainless and so is used a lot in general fabrication.
3.What is structural alloy?
Structural-alloys is a term used in the construction and building industry to refer to metals that are specifically designed and engineered for use in load-bearing structures.
4.What is alloy steel?
Alloy steel is steel that is alloyed with a variety of elements in amounts between 1.0% and 50% by weight, typically to improve its mechanical properties.
5.Is MS stronger than SS?
Stainless steels is designed with a higher content of chromium with other constituent alloys like copper, nitrogen, nickel, molybdenum, and a few others. SS is stronger than alloys of mild steel.



















