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:

inner_diameter = 6.35
outer_diameter = 14
nut_step_shape_degrees = 45
thread_step = 2
type = washer
non_thread_length = 0
nut_thread_step = 2
thread_length = 25
wing_ratio = 1
resolution = 0.5
nut_height = 6
texture = exclude
nut_diameter = 12
nut_thread_outer_diameter = 9
thread_outer_diameter = 8
head_diameter = 12
head_type = hex
thickness = 1.6
non_thread_diameter = 0
nut_resolution = 0.5
nut_type = normal
step_shape_degrees = 45
drive_diameter = 5
head_height = 5
drive_type = socket
countersink = 2
slot_width = 1
facets = 6
slot_depth = 2