Hat Features:

Wilwood's HD 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. HD hats feature a straight bell construction with a flanged rotor mount ring. 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.

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The HD hat configurations are divided into two groups. There are threaded hole hats for use with through-hole mount rotors, and there are through-hole mount hats for use with threaded hole rotors. When used with matching Wilwood rotor hardware, these hats provide solid mounting for a wide range of custom and competition disc brake applications. Use the ordering information link to match the rotor mount, lug pattern, offset, and the other dimensions necessary for each application.
Ordering Information, HD Fixed Mount Aluminum Hats For 5/16-24 Threaded Hole Rotors:
Rotor Bolt Circle
Wheel Lug Pattern
Hat Offset
Stud Hole Diameter
Center Hole I.D.
Face Thickness
Clearence I.D.
Mount Hole
Hat Part Number
Rotor Bolt Kit Number
8 x 7.62"
6 x 5.00"
2.00"
.64"
3.50"
.25"
6.50"
.323"
170-0089
230-0150
8 x 7.62"
5 x 5.00"
2.50"
.64"
3.06"
.25"
6.31"
.323"
170-0030
230-0150
8 x 7.62"
5 x 5.00"
2.12"
.64"
3.06"
.25"
6.31"
.323"
170-0031
230-0150
8 x 7.62"
5 x 4.50/4.75 /5.00"

2.00"

.52"

3.06"
.25"
6.50"
.323"
170-1827
230-0150
8 x 7.62"
5 x 4.75"

1.50"

.51"
2.85"
.50"
6.51"
.323"
170-0176
230-0150
8 x 7.62"
5 x 4.50"

2.10"

.50"

2.75"
.25"

6.31"
.323"
170-0636
230-0150
8 x 7.62"
5 x 4.50"
1.38"

.67"
3.23"
.25"

6.27"
.323"
170-0635
230-0150
8 x 7.62"
5 x 4.50"

1.25"
.52"

3.06"
.25"

6.32"
.323"
170-3265
230-0150
8 x 7.62"
4 x 4.25"

2.00"

.52"
3.06"
.29"

6.50"
.323"
170-2637
230-0150
8 x 7.62"
4 x 4.25"

1.25"

.52"

3.06"
.29"

6.32"
.323"
170-3149
230-0150
8 x 7.62"
Undrilled

2.00"
-

2.78"
.25"

6.50"
.323"
171-2233
230-0150
Ordering Information, HD Fixed Mount Aluminum Hats For 5/16" Through-Hole Rotors:
Rotor Bolt Circle
Wheel Lug Pattern
Hat Offset
Stud Hole Diameter
Center Hole I.D.
Face Thickness
Clearence I.D.
Mount Hole
Hat Part Number
Rotor Bolt Kit Number
8 x 7.00"
5 x 4.75/5.00"
1.96"
.70"
3.06"
.25"
6.14"
5/16-18
170-5244
230-0233D
8 x 7.00"
5 x 4.50/4.75 /5.00"
1.96"
.52"
3.06"
.25"
6.14"
5/16-18
170-0208
230-0233D
8 x 7.00"
5 x 4.50/4.75 /5.00"
1.77"
.52"
3.06"
.25"
6.14"
5/16-18
170-0357
230-0233D
8 x 7.00"
5 x 4.50/4.75 /5.00"
1.71"
.52"
3.06"
.25"
6.14"
5/16-18
170-0259
230-0233D
8 x 7.00"
5 x 4.50/4.75 /5.00"
1.59"
.52"
3.06"
.25"
6.14"
5/16-18
170-0317
230-0233D
8 x 7.00"
5 x 4.50/4.75 /5.00"
1.41"
.52"
3.06"
.50"
6.14"
5/16-18
170-0764
230-0233D
8 x 7.00"
4 x 4.50"
1.41"
.51"
2.68"
.50"
6.14"
5/16-18
170-1754
230-0233D
8 x 7.00"
Undrilled
1.96"
-
3.06"
.25"
6.14"
5/16-18
171-3753
230-0233D
8 x 7.00"
Undrilled
1.71"
-
3.06"
.25"
6.14"
5/16-18
171-3754
230-0233D
8 x 7.00"
Undrilled
1.59"
-
3.06"
.25"
6.14"
5/16-18
171-3755
230-0233D
8 x 7.00"
Undrilled
1.41"
-
2.78"
.50"
6.14"
5/16-18
171-2234
230-0233D