Black Surface 4140 Tool Steel Round Bar Up To 700mm Diameter

1.7225 Forged tool steel round bar 450mm diameter black surface

1. 4140 alloy steel is a 1% chromium - molybdenum medium hardenability general purpose high tensile steel - generally supplied hardened and tempered in the tensile range of 850 - 1000 Mpa (condition T).4140 is now available with improved machinability, which greatly increases feeds and/or speeds, while also extending tool life without adversley affecting mechanical properties.

Pre hardened and tempered 4140 can be further surface hardened by flame or induction hardening and by nitriding.

4140 is used extensively in most industry sectors for a wide range of applications such as:

Adapters, Arbors, Axle Shafts, Bolts, Crankshafts, Connection Rods, Chuck Bodies, Collets, Conveyor Pins & Rolls, Ejector Pins, Forks, Gears, Guide Rods, Hydraulic Shafts & Parts,Lathe Spindles, Logging Parts, Milling Spindles, Motor Shafts, Nuts, Pinch Bars, Pins Various, Pinions, Pump Shafts, Rams, Sockets, Spindles, Sprockets, Studs, Tool Holders, Torsion Bars, Worms etc..

2. Common 4140 Steel Specifications

3. 4140 Steel Bar Chemical Composition

4. Mechanical Properties of AISI Alloy 4140 Steel Bar, Plates, Square

5. Forging

Preheat the steel carefully, heat to 1150 oC – 1200 oC maximum, hold until temperature is uniform throughout the section.
Do not forge below 850 oC.Following forging operation the work piece should be cooled as slowly as possible.

1.7225 Forged tool steel round bar 450mm diameter black surface

1. 4140 alloy steel is a 1% chromium - molybdenum medium hardenability general purpose high tensile steel - generally supplied hardened and tempered in the tensile range of 850 - 1000 Mpa (condition T).4140 is now available with improved machinability, which greatly increases feeds and/or speeds, while also extending tool life without adversley affecting mechanical properties.

Pre hardened and tempered 4140 can be further surface hardened by flame or induction hardening and by nitriding.

4140 is used extensively in most industry sectors for a wide range of applications such as:

Adapters, Arbors, Axle Shafts, Bolts, Crankshafts, Connection Rods, Chuck Bodies, Collets, Conveyor Pins & Rolls, Ejector Pins, Forks, Gears, Guide Rods, Hydraulic Shafts & Parts,Lathe Spindles, Logging Parts, Milling Spindles, Motor Shafts, Nuts, Pinch Bars, Pins Various, Pinions, Pump Shafts, Rams, Sockets, Spindles, Sprockets, Studs, Tool Holders, Torsion Bars, Worms etc..

2. Common 4140 Steel Specifications

3. 4140 Steel Bar Chemical Composition

4. Mechanical Properties of AISI Alloy 4140 Steel Bar, Plates, Square

5. Forging

Preheat the steel carefully, heat to 1150 oC – 1200 oC maximum, hold until temperature is uniform throughout the section.
Do not forge below 850 oC.Following forging operation the work piece should be cooled as slowly as possible.

1.Supply Form & Size & Tolerance

Remark:Tolerance can be customized as per requests

2.Chemical Composition

3.Physical Property

4. Mechanical Property

5.High Temperature Strength

6. Forging

Forging temperature should be carried out between 900℃-1200℃, the lower the forging end temperature, the finer the grain, the temperature should be kept uniform before forging, the minimum forging temperature is 850℃, so don't forge below 850℃.

7. Normalizing

Normalizing is used to refine the forging structure that may not be cooled uniformly after forging and is considered as a conditioning treatment before final heat treatment. normalizing temperature of AISI 4140 steel should be carried out between 870℃-900℃.

8. Annealing

After forging, AISI 4140 steel may be annealed. The annealing temperature should be carried out between 800°C-850°C. Keep the steel fully heated for a suitable time. Cool slowly in the furnace. This treatment will result in a structure suitable for machining. The maximum hardness is 241 HB.

9. Quenching

This heat treatment will obtain a martensitic structure after quenching. It should be carried out between 840°C and 875°C, keeping the steel for a suitable time to heat it sufficiently, soaking it for 10-15 minutes per 25 mm section and quenching it in oil, water or polymer as required.

10. Tempering

Tempering is usually done to remove stresses from the hardening process, but mainly to obtain the desired hardness and mechanical properties. AISI 4140 is carefully heated to a suitable temperature, usually between 550°C and 700°C, and every 25 mm scale section is immersed at this temperature for 2 hours and then cooled in air. tempering between 250°C and 375°C is unavoidable, as tempering in this range can severely reduce impact values and lead to temper brittleness.

11. Applications

AISI 4140 steel has many applications in forgings for the aerospace, oil and gas, automotive, agricultural and defense industries.
Typical applications for 4140 steel include: forged gears, spindles, fixtures, clamps, collars, conveyor components, crowbars, logging components, shafts, sprockets, studs, pinions, pump shafts, sliders, and ring gears.

AISI 4140 Steel Buying Guide
Are you in the market for AISI 4140 steel, but you're not sure why you need it? If so, we are now here to prepare a comprehensive guide to its properties, composition, applications and more.

4140 steel is known for its versatility and strength. Read our expert guide to gain more insight into AISI 4140 steel. Here are the questions you may have about 4140 steel before you buy.

By the end of this guide, you will not only be proficient at seeing and distinguishing 4140 steel, but you will also have the knowledge to find its best source.

Under which conditions should normalizing of AISI 4140 steel be performed?

Normalizing of steel is a method of heating the steel to a temperature above the ferrite to austenite transformation range, followed by air cooling below the transformation range temperature.

As a conditioning treatment, the purpose of the initial heat treatment is to improve machinability, remove internal stresses and prepare a good metallographic organization for the final heat treatment.

After the hot working operation, AISI 4140 steel is generally normalized to obtain fine grain size and uniform carbide distribution prior to the final heat treatment. For important forgings with complex shapes, high-temperature tempering (550-650°C) is required after normalizing. The purpose of high-temperature tempering is to eliminate the stresses generated during normalizing and cooling, and to improve toughness and plasticity.

For common structural parts made from AISI 4140 steel without stress and with low performance requirements, the normalized workpiece will have better overall mechanical properties compared to the annealed treatment. Normalizing treatment can be used as the final heat treatment to reduce the process, save energy and improve production efficiency.