Customized version of http://www.thingiverse.com/thing:193647

Created with Customizer! http://www.thingiverse.com/apps/customizer/run?thing_id=193647

Using the following options:

head_type = hex
socket_facets = 6
thread_step = 2
slot_depth = 2
step_shape_degrees = 45
nut_thread_outer_diameter = 4.125
type = washer
socket_depth = 3.5
head_diameter = 12
nut_type = normal
outer_diameter = 10
drive_type = socket
thickness = .5
slot_width = 1
nut_diameter = 8
drive_diameter = 5
nut_step_shape_degrees = 45
resolution = 0.5
inner_diameter = 4.5
facets = 6
texture = exclude
nut_thread_step = .7
non_thread_diameter = 0
countersink = 2
nut_height = 4
head_height = 5
wing_ratio = 1
non_thread_length = 0
thread_length = 25
thread_outer_diameter = 8