Hat No: 170-0635

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Pro-Street Hat - Standard
Prod #: 170-0635
Price: $134.93
Pro-Street Hat - Standard 170-0635

Hat Dimensions
Mount Hole Type Thru Hole
Rotor Bolt Circle (in) 8 x 7.62
Hat Offset (in) 1.38
Center Reg. (in) 3.23
Hat Type
Material Aluminum
Mount Style Fixed Mount
Finish Black E-Coat
Weight (lbs) 1.8
Bolt Circle Dimensions
Hat Bolt Circle 1 5 X 4.50
Hat Bolt Circle 2
Hat Bolt Circle 3
UPC Number
UPC 889545041279
Application Info
Application Note Pantera
Hat Bolt Kit Part # 230-0150
Application Note
Application Note
Pro-Street Hat - Standard - Product Description

Wilwood's Pro Street Series Fixed Mount Rotor Hats have a long standing reputation for fit, performance, and durability. HD Series hats are manufactured from premium grade aluminum alloys offering high strength, low weight, and show quality appeal. HD hats have not only been a mainstay in many of Wilwood's racing disc brake conversion kits, but they can cover a range of applications from an OE four lug axle shaft to a Grand-National stock car racing hub. Pro Street hats feature a straight bell construction with a flanged rotor mount ring, with through holes for use with threaded-hole, 8 x 7.62 mount rotors. These features combine to provide maximum radial clearance between the caliper body and the hat. This can be a critical factor when trying to squeeze a large caliper inside a small wheel. Many hats offer multi-lug wheel patterns for added versatility. Some hats can be ordered blank for custom axle building and other unique applications.


Threaded hole hats for use with though-hole mount rotors. When used with matching Wilwood rotor hardware, these hats provide solid mounting for a wide range of custom and competition disc brake applications.



Vehicle Applications
Driving Environment Street Rods
Vehicle Sub-Types
Application Duty Heavy Duty
Driving Environment Street Performance
Vehicle Sub-Types Domestic
Application Duty Heavy Duty
Driving Environment Street Performance
Vehicle Sub-Types Import
Application Duty Heavy Duty
Driving Environment Rally
Vehicle Sub-Types
Application Duty Heavy Duty
Driving Environment Road Race
Vehicle Sub-Types
Application Duty Heavy Duty
Driving Environment Drag Racing
Vehicle Sub-Types
Application Duty Heavy Duty
Driving Environment Off Road
Vehicle Sub-Types
Application Duty Heavy Duty
Driving Environment Industrial
Vehicle Sub-Types
Application Duty Heavy Duty

Rotor Hat Dimensions

Additional Hat Dimensions
Rotor Mount Hole Size (in) .323
Shoe I.D. (in)
Clearance I.D. (in) 6.27
Face Thickness (in) 0.25
Hat Stud Diamenter - BC 1 (in) 0.67
Hat Stud Diamenter - BC 2 (in)
Hat Stud Diamenter - BC 3 (in)
Additional Notes

Wilwood Compatible Rotors

Drilled Steel Rotor

Rotor Dimensions
Rotor Diameter Range 12
Rotor Width Range 0.31

Drilled Steel Rotor Rotors

Steel rotors have applications in all types of motorsports. Steel rotors provide a durable lightweight option in applications where sustained temperatures remain in the low to moderate range, and high heat spikes are only observed on an intermittent basis. This could be anything from a hard stopping drag race car at the end of a quarter mile, or a high speed stock car coming in from a qualifier at a super speedway. Steel rotors can also be found in lighter weight open wheel cars such as sprints and modifieds, and a variety of light weight, open wheel road course racers. A special alloy and proprietary manufacturing processes give these rotors high resistance to thermal distortion with excellent friction and wear characteristics against the pads. View Steel Rotors
GT 36 Curved Vane Rotor

Rotor Dimensions
Rotor Diameter Range 12.19
Rotor Width Range 0.81

GT 36 Curved Vane Rotor Rotors

GT-36 curved vane rotors are built for the extreme conditions of professional motorsports. The superior heat absorption and dissipation characteristics of these heavy wall directional vane rotors are the keys to preventing heat fade and realizing long service life from the rotors and pads. All rotors are cast from premium grade, long grain carbon iron for long wear, thermal stability, and resistance to distortion. Every GT rotor is fully detail machined to eliminate stress points and unnecessary weight away from the pad sweep face. The faces and O.D. are precision turned to less than .001" for flatness, parallelism, and run-out. An asymmetrical face slot pattern provides smoother engagement through reduced harmonics and improved thermal balance between the I.D. and O.D. of the rotor. Every rotor is then individually dynamic balanced to provide vibration free performance at any speed. These rotors provide the highest cooling capacity and longest service life for extreme braking short tracks and road course competition. View GT Rotors
GT 36 Curved Vane Rotor

Rotor Dimensions
Rotor Diameter Range 12.19
Rotor Width Range 0.81

GT 36 Curved Vane Rotor Rotors

Wilwood's GT 36 Curved Vane Spec-37 rotors are manufactured from a proprietary iron alloy developed to withstand extreme temperatures with the highest possible degree of resistance against distortion, warping, cracking, and wear. The formulation for this alloy is a derivative of technology and materials that were significant in the development of the extreme duty military spec rotors that are manufactured by Wilwood. Combined with our proven GT Series asymmetrical face slot pattern and individual dynamic balancing, you are assured the smoothest braking available. View GT Rotors
GT 48 Curved Vane Rotor

Rotor Dimensions
Rotor Diameter Range 12.72
Rotor Width Range 1.25

GT 48 Curved Vane Rotor Rotors

Wilwood's GT 48 Curved Vane Spec-37 rotors are manufactured from a proprietary iron alloy developed to withstand extreme temperatures with the highest possible degree of resistance against distortion, warping, cracking, and wear. The formulation for this alloy is a derivative of technology and materials that were significant in the development of the extreme duty military spec rotors that are manufactured by Wilwood. Combined with our proven GT Series asymmetrical face slot pattern and individual dynamic balancing, you are assured the smoothest, vibration free performance at any speed. These rotors provide the highest cooling capacity and longest service life for extreme braking short tracks and road course competition. View GT Rotors
GT 48 Curved Vane Rotor

Rotor Dimensions
Rotor Diameter Range 13.06
Rotor Width Range 1.38

GT 48 Curved Vane Rotor Rotors

Wilwood's GT 48 Curved Vane Spec-37 rotors are manufactured from a proprietary iron alloy developed to withstand extreme temperatures with the highest possible degree of resistance against distortion, warping, cracking, and wear. The formulation for this alloy is a derivative of technology and materials that were significant in the development of the extreme duty military spec rotors that are manufactured by Wilwood. Combined with our proven GT Series asymmetrical face slot pattern and individual dynamic balancing, you are assured the smoothest, vibration free performance at any speed. These rotors provide the highest cooling capacity and longest service life for extreme braking short tracks and road course competition. View GT Rotors
HD 48 Curved Vane Rotor

Rotor Dimensions
Rotor Diameter Range 12.19
Rotor Width Range 1.25

HD 48 Curved Vane Rotor Rotors

Wilwood's HD 48 Curved Vane Spec-37 rotors are are manufactured from a proprietary iron alloy developed to withstand extreme temperatures with the highest possible degree of resistance against distortion, warping, cracking, and wear. The formulation for this alloy is a derivative of technology and materials that were significant in the development of the extreme duty military spec rotors that are manufactured by Wilwood. Our HD Series preparation includes full detail machining and smooth pad contact faces without slots. View HD Rotors
Solid Steel Rotor

Rotor Dimensions
Rotor Diameter Range 12
Rotor Width Range 0.31

Solid Steel Rotor Rotors

Steel rotors have applications in all types of motorsports. Steel rotors provide a durable lightweight option in applications where sustained temperatures remain in the low to moderate range, and high heat spikes are only observed on an intermittent basis. This could be anything from a hard stopping drag race car at the end of a quarter mile, or a high speed stock car coming in from a qualifier at a super speedway. Steel rotors can also be found in lighter weight open wheel cars such as sprints and modifieds, and a variety of light weight, open wheel road course racers. A special alloy and proprietary manufacturing processes give these rotors high resistance to thermal distortion with excellent friction and wear characteristics against the pads. View Steel Rotors
SRP Drilled Performance Rotor

Rotor Dimensions
Rotor Diameter Range 12.19
Rotor Width Range 0.81

SRP Drilled Performance Rotor Rotors

SRP Drilled Performance Rotors feature a specially engineered directional cross drill and face slot pattern that improve brake response and pad performance throughout the entire range of light to heavy braking. The venting and cleaning action of the holes and slots will reduce pad glaze and disperse gasses and heat generated during the pad to rotor interface. The holes and slots also inhibit irregular pad compound build-up on the rotor faces resulting in smoother engagement and improved pedal response in all conditions. The material removed also contributes to lower rotating and unsprung suspension weight. View SRP Rotors
SRP Drilled Performance Rotor

Rotor Dimensions
Rotor Diameter Range 12.19
Rotor Width Range 0.81

SRP Drilled Performance Rotor Rotors

SRP Drilled Performance Rotors feature a specially engineered directional cross drill and face slot pattern that improve brake response and pad performance throughout the entire range of light to heavy braking. The venting and cleaning action of the holes and slots will reduce pad glaze and disperse gasses and heat generated during the pad to rotor interface. The holes and slots also inhibit irregular pad compound build-up on the rotor faces resulting in smoother engagement and improved pedal response in all conditions. The material removed also contributes to lower rotating and unsprung suspension weight. View SRP Rotors
Ultralite 32 Curved Vane Rotor

Rotor Dimensions
Rotor Diameter Range 12.19
Rotor Width Range 1.25

Ultralite 32 Curved Vane Rotor Rotors

Ultra-Light UL-32 directional vane rotors provide an excellent balance of efficient cooling and lower rotating mass on hard braking dirt tracks or rear axle service on pavement cars. UL rotors are cast from premium grade, long grain carbon iron for long wear, high thermal stability, and resistance to distortion. UL-32 rotors are production machined and well suited to a wide range of sportsman racing categories. View Ultralite Rotors
Ultralite 32 Vane Rotor

Rotor Dimensions
Rotor Diameter Range 11.75
Rotor Width Range 0.75

Ultralite 32 Vane Rotor Rotors

Ultra-Light UL straight vane rotors provide high value performance and rugged durability for a wide range of competition, high performance, and sport driving applications. Don't confuse these rotors with bargain priced off-brand named parts. Wilwood's modern manufacturing capability, combined with large scale economy, make it possible to offer this level of quality and performance at such an affordable price. View Ultralite Rotors
Ultralite HP 32 Vane Rotor

Rotor Dimensions
Rotor Diameter Range 12.19
Rotor Width Range 0.81

Ultralite HP 32 Vane Rotor Rotors

Ultra-Light ULHP-32 straight vane rotors provide an excellent balance of efficient cooling and lower rotating mass on hard braking dirt tracks or rear axle service on pavement cars. UL rotors are cast from premium grade, long grain carbon iron for long wear, high thermal stability, and resistance to distortion. ULHP-32 rotors offered the added performance and smoother operation of precision turned faces with less than .001" variation in flatness, parallelism, or run-out. View Ultralite Rotors



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