Automotive Performance Materials Guide

Spec-37 iron is a premium iron casting material used by Wilwood in many of its performance brake rotors.

Wilwood describes its Spec-37 rotor construction as a premium-grade, heavy-wall casting intended for performance applications ranging from street use through moderate-temperature racing. On applicable rotors, the material is combined with internal vane structures designed to manage the heat generated during braking.

Common Characteristics

• Heavy-duty iron rotor construction
  
• Designed to withstand repeated braking loads
  
• Good thermal stability for performance braking
  
• Used in both street-performance and racing brake applications
  
• Often paired with straight or curved internal cooling vanes
  

Common Automotive Uses

• Performance brake rotors
  
• Racing brake rotors
  
• Wilwood brake systems

6061 aluminum is a widely used aluminum alloy found in automotive, motorsports, fabrication, and fluid-transfer components.

It offers a useful combination of relatively low weight, strength, corrosion resistance, and machinability. Because of these characteristics, it is commonly CNC-machined into fittings, adapters, brackets, and other performance components.

Common Characteristics

• Lightweight compared with steel
  
• Good corrosion resistance
  
• Easily machined
  
• Suitable for anodizing
  
• Good general-purpose structural strength
  
• Widely used in performance fabrication
  

Common Automotive Uses

• AN fittings
  
• Hose ends
  
• Adapter fittings
  
• Brackets
  
• Intake components
  
• Fluid-system components
  
• Fabricated aluminum parts
  

For example, Vibrant Performance manufactures its high-flow PTFE hose ends from CNC-machined 6061 aluminum alloy and applies a black hard-anodized finish.

PTFE, or polytetrafluoroethylene, is a fluoropolymer commonly used as the inner liner in performance fluid-transfer hoses.

PTFE is valued for its chemical resistance and ability to handle a broad range of automotive fluids. PTFE-lined hoses are commonly paired with fittings specifically designed to compress and seal against the PTFE liner.

Common Characteristics

• High chemical resistance
  
• Low friction
  
• Resistant to many automotive fuels and fluids
  
• Suitable for a broad range of operating temperatures
  
• Low permeability compared with many conventional rubber hose materials
  

Common Automotive Uses

• Fuel hoses
  
• Ethanol-compatible fuel systems
  
• Oil lines
  
• Coolant lines
  
• Power-steering plumbing
  
• Nitrous systems
  
• Performance fluid-transfer systems
  

PTFE hose ends should be matched to PTFE-specific hose. For example, Vibrant's PTFE hose ends use an aluminum olive that compresses against the PTFE liner to form the connection.

EPDM, or ethylene propylene diene monomer, is a synthetic elastomer widely used in automotive belts, hoses, seals, and weather-resistant components.

EPDM is particularly valued for its flexibility and resistance to heat, ozone, weathering, and cracking.

Common Characteristics

• Strong resistance to heat
  
• Resistant to ozone and weather exposure
  
• Good flexibility
  
• Good resistance to cracking
  
• Long service life in suitable applications
  

Common Automotive Uses

• Serpentine belts
  
• Accessory drive belts
  
• Coolant hoses
  
• Weather seals
  
• Various rubber components
  

Gates uses EPDM compounds in many of its automotive Micro-V belts and specifically highlights the material's wear and heat resistance.

HNBR, or hydrogenated nitrile butadiene rubber, is a high-performance elastomer used where greater resistance to heat, oil, fuel, wear, and mechanical stress is required.

It is commonly found in performance timing belts, seals, hoses, and other components exposed to demanding engine environments.

Common Characteristics

• High heat resistance
  
• Good oil resistance
  
• Good wear resistance
  
• Strong mechanical properties
  
• Suitable for demanding engine environments
  

Common Automotive Uses

• Performance timing belts
  
• Fuel-system components
  
• Engine seals
  
• Specialty hoses
  

Gates uses HNBR in automotive applications including fuel hose construction and high-performance belt products.

Aramid fiber is a high-strength synthetic reinforcing material used where low stretch, high tensile strength, and resistance to repeated loads are important.

In automotive components, aramid fibers may be used as tensile cords or reinforcement within belts and hoses rather than as the entire component.

Common Characteristics

• High tensile strength
  
• Low stretch
  
• Lightweight
  
• Good fatigue resistance
  
• Suitable for high-load reinforcement
  

Common Automotive Uses

• Timing belt reinforcement
  
• Serpentine belt tensile cords
  
• CVT belts
  
• Reinforced hoses
  
• Performance drive belts
  

Gates uses aramid reinforcement in several belt products, including demanding automotive accessory-drive applications.

Stainless steel is a family of corrosion-resistant steel alloys commonly used throughout automotive and motorsports applications.

Different stainless grades have different properties, so the exact alloy matters when evaluating heat resistance, corrosion resistance, strength, and weldability.

Common Characteristics

• Strong corrosion resistance
  
• Good durability
  
• Heat-resistant grades are available
  
• Suitable for fabrication
  
• Available in numerous alloy grades
  

Common Automotive Uses

• Exhaust systems
  
• Brake lines
  
• Fasteners
  
• Fittings
  
• V-band components
  
• Tubing
  
• Heat shields
  

Common automotive grades include 304 and 321 stainless steel, particularly in exhaust fabrication.

Chromoly steel is an alloy steel containing chromium and molybdenum.

It is commonly selected for automotive components that require high strength without excessive material thickness or weight.

Common Characteristics

• High strength
  
• Good fatigue resistance
  
• Suitable for structural components
  
• Can provide high strength with relatively thin wall sections
  
• Common in racing and motorsports fabrication
  

Common Automotive Uses

• Roll cages
  
• Suspension components
  
• Control arms
  
• Chassis components
  
• Axles
  
• Fasteners
  
• Fabricated motorsports parts

Cast iron is an iron-based material widely used in automotive components where durability, wear resistance, thermal capacity, and cost are important.

Common Characteristics

• Excellent wear resistance
  
• Good thermal capacity
  
• Good vibration damping
  
• Relatively heavy
  
• Well suited to casting complex shapes
  

Common Automotive Uses

• Brake rotors
  
• Engine blocks
  
• Exhaust manifolds
  
• Drums
  
• Heavy-duty housings