AVIATIONEU NEW ERA ST4130 Round Tubes Normalized-Seamless
  • AVIATIONEU NEW ERA ST4130 Round Tubes Normalized-Seamless
  • AVIATIONEU NEW ERA 4130-4140 Steel Alloy Tubing Features
  • AVIATIONEU NEW ERA 4130-4140 Steel Alloy Tubing Applications

AVIATIONEU NEW ERA 4130 Alloy Steel (Chromoly) Round Tubes Seamless (Normalized) SKU: AVEUNE-RNDTB-ST4130-NRZSML

Steel alloy 4130 (ST4130), also known as Chrome Moly after the 2 key elements of its composition, chromium, and molybdenum, is a general-purpose alloy steel widely used by the aviation and motorsports industries due to its weldability, fabrication, and mild hardenability in all offered forms (tubes, bars, sheets and plates). They are available in two different material states (Normalized and Annealed) depending on the process of how the material is heated and cooled.

The Normalized condition (sometimes referred to as "Condition N") is the harder and stronger condition and is best used when forming is not needed. Normalizing relieves internal stress on steel and improves toughness in steels that may harden after the cold working process. The Annealed condition (sometimes referred to as "Condition A") is the softer and formable condition and is best used when forming is needed. Annealing relieves internal stresses, softens and makes the material more ductile.

4130 alloy steel (Chrome Moly) seamless round tubes are offered as part of our own branded (AVIATIONEU NEW ERA) product lines in Normalized (N )  or Annealed (A) conditions indicated by the letters "NRZ" and  "ANL" respectively in the product reference code (SKU). They have been for years the standard of the aircraft industry. These tubes offer good strength and weldability without compromising steel abrasion or impact resistance and can also be made even stronger through heat treatment. They are commonly used in in structural applications, gears, fasteners, and aircraft exteriors. Tensile Strength: 90,000 PSI. Available in a range of outer diameters, wall thicknesses and pre-cut lengths in inches or cut to order (CTO) lengths of 12 inches (1 foot)) or multiples. Apperating price of CTO tubes is per foot (12 inches). Depending on the supplier, they comply with different standards/specifications, such as MIL-T6736 standard or ASTM/A S1906 specifications. Unless otherwise mentioned, there is additional cost if manufacturing test reports are required. For additional information, please refer to the supplied documentation or contact us.

Outer Diameter OD (in./")
Thickness (in./")
Length (in./")

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100 7.5% Up to €120.00

Steel alloy 4130 also known as ST4130, AISI 4130 or Chrome Moly is a general-purpose alloy steel containing molybdenum and chromium as strengthening agents. This alloy is widely used by the aviation and motorsports industries due to its weldability (due to its relatively low carbon content) fabrication, and mild hardenability in all offered forms/shapes (tubes, bars, sheets and plates). The alloy can be hardened by heat treatment. Typical uses include structural such as aircraft engine mounts and welded tubing applications.

Available in two different material states, also called conditions (Normalized and Annealed) depending on the process of how the material is heated and cooled. The cooling rate of normalizing (sometimes referred to as "Condition N") is slightly faster than that of annealing (sometimes referred to as "Condition A"), and the degree of supercooling is larger. Also, the structure obtained after normalizing is relatively fine, and the strength and hardness are higher than that of annealing.

The choice between Normalizing and Annealing

Machinability

This alloy is readily machined by conventional methods. Machinability is best with the alloy in the normalized and tempered condition. Although the alloy may be machined in the fully heat treated condition, machinability becomes more difficult with increasing strength (hardness) of the alloy.The hardness after normalizing is significantly higher than that of annealing, and it is difficult to perform cutting processing. Normalizing relieves internal stress on steel and improves toughness in steels that may harden after the cold working process. The Annealed condition is the softer and formable condition and is best used when forming and improved machinability is needed. Annealing relieves internal stresses, softens and makes the material more ductile.

Forming

Formability is best in the annealed condition for which the ductility is very good, Bend radii of 1t on annealed sheet material may be made. The harder and stronger Normalized condition is best used when forming is not needed.  

Welding

4130 alloy is noted for its weldability by all of the commercial methods.

Heat Treatment

Heating at 1600 F followed by an oil quench will harden the 4130 alloy. For best results a normalizing pre-hardening heat treatment may be used at 1650 to 1700 F followed by the 1600 F soak and oil quench.

Forging

Forge at 2200 F maximum down to 1750 F.

Hot Working

4130 in the annealed condition has excellent ductility. Thus it is usually not necessary to do hot working to form parts. If hot working is needed it can be done in the range of 2000 F to 1500 F.

Cold Working

Cold working by conventional methods is readily accomplished on this alloy.

Annealing

4130 (and most of the other low alloy steels) may be annealed at 1550 F for a time long enough to allow thorough heating of the section size. It should then be cooled in the furnace at a rate of less than 50 F per hour down to 900 F, followed by air cooling from 900 F.

Tempering

Tempering is done to restore some of the ductility that may be lost after the hardening heat treatment and quench. Alloy 4130 is tempered at between 750 F and 1050 F, depending upon the strength level desired. The lower the tempering temperature the greater the strength.

Hardening

Hardening is accomplished by heat treatment or by cold working.

Properties

4130 (Chromoly) Normalized Alloy Steel

Ultimate Tensile Strength, psi 97,200 (min)

Yield Strength, psi 63,100 (min)

Elongation 25.5% (min)

Rockwell Hardness B92 (min)

4130 (Chromoly) Annealed Alloy Steel

Tensile Strength, psi 81,200  (min)

Yield Strength, psi 52,200  (min)

Elongation 28.2%  (min)

Rockwell Hardness B82  (min)

Physical Properties

Density (lb / cu. in.) 0.283

Specific Gravity 7.8

Specific Heat (Btu/lb/Deg F – [32-212 Deg F]) 0.114

Melting Point (Deg F) 2610

Thermal Conductivity 22.3

Mean Coeff Thermal Expansion 7

Modulus of Elasticity Tension 29

ST4130RNDTB-NSML-OD0.25-TH0.035-12

Data sheet

Certification/Approval
Manufacturer test reports can be available at additonal cost.
Taric
73079900 Other tube or pipe fittings of iron or steel, other than stainless steel
Unit of Measurement (UOM) / Sale
Inch (in./")
Standard/Specification
MIL -T-6736

Specific References

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