7075-T6 aluminum round bar represents the pinnacle of high-strength aluminum alloys, offering an exceptional combination of strength, hardness, and stress resistance for aerospace, defense, and high-performance mechanical applications:

Primary Alloying Elements:

Zinc (Zn): 5.1-6.1% (principal strengthening element)

Magnesium (Mg): 2.1-2.9% (enhances precipitation hardening)

Copper (Cu): 1.2-2.0% (improves strength and stress resistance)

Chromium (Cr): 0.18-0.28% (corrosion resistance and grain structure control)

Base Material:

Aluminum (Al): ≥87.1% (balance)

Controlled Impurities:

Iron (Fe): ≤0.50% max

Silicon (Si): ≤0.40% max

Manganese (Mn): ≤0.30% max

Titanium (Ti): ≤0.20% max

Other elements: ≤0.05% each, ≤0.15% total

Premium Manufacturing Process:

Melt Preparation:

Primary high-purity aluminum (99.7% minimum)

Precise alloying element additions with ±0.1% tolerance

Advanced filtration through ceramic foam filters (30-40 ppi)

SNIF degassing treatment (hydrogen < 0.10 ml/100g)

Grain refinement with Al-Ti-B master alloy

Direct-chill (DC) semi-continuous casting

Homogenization:

460-480°C for 24-48 hours

Uniform temperature control: ±5°C

Controlled cooling rate: 20-30°C/hour

Dissolution of coarse intermetallics

Microsegregation elimination

Hot Working Process:

Breakdown forging/rolling: 385-415°C

Intermediate operations: 370-400°C

Final hot working: 350-380°C

Computerized temperature monitoring throughout

Solution Heat Treatment:

465-485°C for 1-2 hours (diameter dependent)

Temperature uniformity: ±3°C

Rapid transfer to quenching medium

Maximum transfer time: 10 seconds

Quenching:

Cold water (10-30°C)

Agitation for uniform cooling

Minimum cooling rate: 100°C/sec at surface

Cold Stretching (T651):

1.5-3.0% permanent deformation

Stress relief and straightening

Dimensional accuracy enhancement

Artificial Aging (T6):Dual-stage aging process:

First stage: 110-130°C for 4-6 hours

Second stage: 165-175°C for 8-12 hours

Temperature uniformity: ±3°C

Controlled cooling after aging

Final Processing:

Precision centerless grinding (optional)

Stress-free straightening

Nondestructive testing

Surface treatment and protection

Full process traceability with computerized quality monitoring at all stages.

 

 

 

Property	Minimum	Typical Range	Test Method
Ultimate Tensile Strength	570 MPa	580-600 MPa	ASTM E8
Yield Strength (0.2%)	500 MPa	510-540 MPa	ASTM E8
Elongation (2 inch)	7%	8-11%	ASTM E8
Hardness (Brinell)	150 HB	155-165 HB	ASTM E10
Fatigue Strength (5×10⁸)	160 MPa	170-190 MPa	ASTM E466
Shear Strength	330 MPa	340-360 MPa	ASTM B769
Fracture Toughness (K₁c)	24 MPa√m	25-29 MPa√m	ASTM E399
Compressive Yield Strength	520 MPa	530-550 MPa	ASTM E9
Modulus of Elasticity	71.7 GPa	71.7-72.4 GPa	ASTM E111

 

Property Distribution:

Longitudinal to transverse property ratio: 1.00:0.95 (strength), 1.00:0.75 (elongation)

Variation across diameter: <5% for diameters up to 75mm, <8% for diameters >75mm

Core to surface hardness variation: <10 HB for diameters up to 100mm

Property stability: <3% strength reduction after 10,000 hours at 100°C

Stress Corrosion Cracking Threshold: 125-175 MPa (dependent on environment)

 

 

 

Key Microstructural Features:

Grain Structure:

Partially recrystallized structure with elongated grains

ASTM grain size 7-9 (32-16μm)

Aspect ratio: 2:1 to 4:1 (length:width)

Well-controlled grain flow pattern

Precipitate Distribution:

MgZn₂ (η/η’) strengthening precipitates: 5-15nm

CuMgAl₂ (S-phase) precipitates

Al₇Cu₂Fe intermetallics: Controlled size and distribution

Al₁₂Mg₂Cr dispersoids: 50-200nm

Texture Development:

Strong <111> and <100> fiber textures

Texture intensity: 3-8× random

Optimized for maximum strength in primary loading directions

Special Features:

Precipitation-hardened microstructure

Minimal precipitate-free zones (PFZs) at grain boundaries

Controlled distribution of coarse intermetallics

Fine dispersoid distribution for recrystallization control

 

 

 

Parameter	Standard Range	Precision Tolerance	Commercial Tolerance	Test Method
Diameter	10-250 mm	±0.10mm up to 30mm	±0.20mm up to 30mm	Micrometer
		±0.4% above 30mm	±0.7% above 30mm
Ovality	N/A	50% of diameter tolerance	75% of diameter tolerance	Micrometer
Length	2000-6000 mm	±2mm	±5mm	Tape measure
Straightness	N/A	0.2mm/m	0.5mm/m	Straightedge
Surface Roughness	N/A	1.6 μm Ra max	3.2 μm Ra max	Profilometer
Cut End Squareness	N/A	0.5° max	1.0° max	Protractor

 

Standard Available Forms:

Diameters: 10mm to 250mm (larger sizes available on request)

Standard Lengths: 2000mm, 3000mm, 4000mm, 6000mm

Custom cut lengths available

Centerless ground bars available for precision applications

Saw-cut ends with protective end caps

 

 

 

Temper Code	Process Description	Optimal Applications	Key Characteristics
T6	Solution heat treated and artificially aged	High-strength applications	Maximum strength and hardness
T651	T6 + stress relieved by stretching	Critical aerospace components	Improved stress corrosion resistance
T73	Overaged for stress corrosion resistance	Corrosion-critical applications	Better SCC resistance with reduced strength
T76	Modified overaging treatment	Balanced properties	Compromise between T6 and T73
T7351	T73 + stress relieved by stretching	Thick sections with residual stress concerns	Dimensional stability with SCC resistance

 

Temper Selection Guidance:

T6/T651: Highest strength requirements

T73/T7351: Stress-corrosion critical applications

T76: Balanced properties for general aerospace applications

 

 

 

Operation	Tool Material	Recommended Parameters	Comments
Turning	Carbide, PCD	Vc=150-300 m/min, f=0.1-0.3 mm/rev	Sharp tools essential
Drilling	HSS-Co, Carbide	Vc=60-120 m/min, f=0.15-0.35 mm/rev	Frequent chip clearing
Milling	Carbide, PCD	Vc=180-350 m/min, fz=0.05-0.15 mm	Climb milling preferred
Tapping	HSS-Co, TiN coated	Vc=10-20 m/min	Thread quality sensitive to heat
Reaming	Carbide, PCD	Vc=40-90 m/min, f=0.1-0.3 mm/rev	H7 tolerance achievable
Thread Milling	Carbide	Vc=100-200 m/min, fz=0.03-0.08 mm	Preferred over tapping for critical threads

 

Fabrication Guidance:

Machinability Rating: 70% (1100 aluminum = 100%)

Surface Finish: Good (Ra 0.8-3.2μm achievable)

Chip Formation: Short to medium chips with proper tooling

Coolant: Water-soluble emulsion preferred (8-10% concentration)

Tool Wear: Moderate with proper parameters

Cutting Forces: Higher than other aluminum alloys

Weldability: Poor (not recommended for structural applications)

Cold Working: Limited formability

Hot Working: Not recommended in T6 condition

Heat Treatment: Can be fully re-heat treated after machining

 

 

 

Environment Type	Resistance Rating	Protection Method	Expected Performance
Industrial Atmosphere	Fair	Anodizing + paint	3-5 years with maintenance
Marine Environment	Poor	Anodizing + chromate + paint	2-3 years with maintenance
High Humidity	Fair	Anodizing Type II	1-2 years without additional protection
Stress Corrosion	Poor in T6, Good in T73	Proper temper selection	Application specific
Exfoliation	Poor	Proper temper + protection	Critical in marine applications
Galvanic Corrosion	Poor with carbon steels	Isolation or sacrificial protection	Requires careful design

 

Surface Protection Options:

Anodizing:

Type I (Chromic): 2-8μm (aerospace grade)

Type II (Sulfuric): 10-25μm (general purpose)

Type III (Hard): 25-75μm (wear resistance)

Sealing options: Hot water, dichromate, nickel acetate

Conversion Coatings:

Chromate per MIL-DTL-5541 Class 1A

Non-chromium alternatives for environmental compliance

Painting Systems:

Epoxy primer + polyurethane topcoat

Aerospace-qualified systems available

Mechanical Protection:

Shot peening for enhanced fatigue and SCC resistance

Glass bead blasting for uniform appearance

 

Property	Value	Design Consideration
Density	2.81 g/cm³	Weight calculation for components
Melting Range	477-635°C	Heat treatment limitations
Thermal Conductivity	130-150 W/m·K	Thermal management design
Electrical Conductivity	33-40% IACS	Electrical applications design
Specific Heat	860 J/kg·K	Thermal mass calculations
Thermal Expansion (CTE)	23.4 ×10⁻⁶/K	Thermal stress analysis
Young’s Modulus	71.7 GPa	Deflection and stiffness calculations
Poisson’s Ratio	0.33	Structural analysis parameter
Magnetic Permeability	~1.00 (non-magnetic)	Electronic applications

 

Design Considerations:

Operating Temperature Range: -70°C to +120°C

Property Retention: Excellent below 100°C, gradual degradation above

Stress Relaxation: Minimal below 100°C

Fatigue Life: Superior to most aluminum alloys

Notch Sensitivity: Moderate to high

Cryogenic Performance: Good strength retention at low temperatures

Vibration Damping: Poor (typical of high-strength aluminum)

 

Standard Testing Procedures:

Chemical Composition:

Optical emission spectroscopy

X-ray fluorescence analysis

Verification of all major elements and impurities

Mechanical Testing:

Tensile testing (longitudinal and transverse)

Hardness testing (Brinell, Rockwell B)

Impact testing (when required)

Fatigue testing (for critical applications)

Dimensional Inspection:

Diameter/ovality at multiple locations

Straightness verification

Length measurement

Nondestructive Testing:

Ultrasonic inspection per AMS-STD-2154

Eddy current testing for surface defects

Penetrant inspection (critical applications)

Microstructural Analysis:

Grain size determination

Intermetallic particle evaluation

Exfoliation corrosion susceptibility (ASTM G34)

Standard Certifications:

Mill Test Report (EN 10204 3.1)

Chemical analysis certification

Mechanical properties certification

Heat treatment certification

Nondestructive testing certification

Material traceability documentation

 

Primary Applications:

Aerospace Components:

Aircraft landing gear components

Wing spars and structural elements

Fuselage frames and bulkheads

Engine mounts and supports

Defense Applications:

Missile components

Weapons systems parts

Armored vehicle components

Tactical equipment fixtures

High-Performance Automotive:

Drive shafts

Suspension components

Connecting rods

Performance-critical fasteners

Industrial Equipment:

High-stress machine parts

Molds for plastic injection

Hydraulic system components

Robotics and automation components

Specialized Applications:

Precision instrument components

High-performance sporting equipment

Rock climbing equipment

Camera mounting systems

Design Advantages:

Exceptional strength-to-weight ratio

Superior fatigue performance

High resistance to mechanical wear

Excellent machining characteristics

Dimensional stability after machining

Reliable performance in high-stress applications

Comprehensive material database for engineering design

Wide availability in standard sizes