"""ISO 4032 hex nut. Envelope: hex prism with a plain bore at the thread's nominal diameter.
It sits on the XY plane, centred on the origin.

Material: property class 8 carbon steel (C35), zinc plated."""
from steve import Model

size = "M3"  # Thread size

# size: (across flats s, height m)
NUTS = {
    'M2': (4.0, 1.6),
    'M2.5': (5.0, 2.0),
    'M3': (5.5, 2.4),
    'M4': (7.0, 3.2),
    'M5': (8.0, 4.7),
    'M6': (10.0, 5.2),
    'M8': (13.0, 6.8),
    'M10': (16.0, 8.4),
    'M12': (18.0, 10.8),
}
NOMINAL = {
    'M2': 2.0,
    'M2.5': 2.5,
    'M3': 3.0,
    'M4': 4.0,
    'M5': 5.0,
    'M6': 6.0,
    'M8': 8.0,
    'M10': 10.0,
    'M12': 12.0,
}
s, m = NUTS[size]
d = NOMINAL[size]

model = Model()
with model.sketch("nut_sketch", on="XY", name="Nut") as sk:
    sk.polygon("hex", (0, 0), s / 2, 6, inscribed=False)
    sk.circle("bore", (0, 0), d / 2)
model.extrude("nut", "nut_sketch", distance=m)
model.material("steel-1c35")  # class 8 nut steel
model.appearance(color="#c9d1d9", metalness=1.0, roughness=0.3)  # clear zinc plating
result = model.result()