"""Socket head cap screw, ISO 4762 (DIN 912), M1.6 to M64, any length.

Envelope model for assemblies: cylindrical head (largest plain-head diameter dk max, height k max), hexagon socket
(nominal key size s, depth t min) and a plain shank at the nominal thread diameter d (the thread is not modelled).
The head's bearing face is on the XY plane at the origin, the head above it, the shank along -Z; `length` is the
nominal length l, measured from under the head.
"""
from steve import Model

size = "M3"  # Thread size
length = 10  # mm Nominal length (under the head)
material = "steel"  # Material

# ISO 4762:2004, Table 1 (official preview p. 4, M1.6-M12:
# https://cdn.standards.iteh.ai/samples/34460/06335046afaf46fb8e84d91a3eda001d/ISO-4762-2004.pdf; all sizes:
# https://fasten.it/en/Norms/Norm/DIN%20EN%20ISO%204762, DIN EN ISO 4762:2004-06). size: (thread d, head diameter dk max, head height k max, hexagon socket s, socket depth t min)
DIMENSIONS = {
    "M1.6": (1.6, 3.0, 1.6, 1.5, 0.7),
    "M2": (2.0, 3.8, 2.0, 1.5, 1.0),
    "M2.5": (2.5, 4.5, 2.5, 2.0, 1.1),
    "M3": (3.0, 5.5, 3.0, 2.5, 1.3),
    "M4": (4.0, 7.0, 4.0, 3.0, 2.0),
    "M5": (5.0, 8.5, 5.0, 4.0, 2.5),
    "M6": (6.0, 10.0, 6.0, 5.0, 3.0),
    "M8": (8.0, 13.0, 8.0, 6.0, 4.0),
    "M10": (10.0, 16.0, 10.0, 8.0, 5.0),
    "M12": (12.0, 18.0, 12.0, 10.0, 6.0),
    "M14": (14.0, 21.0, 14.0, 12.0, 7.0),
    "M16": (16.0, 24.0, 16.0, 14.0, 8.0),
    "M20": (20.0, 30.0, 20.0, 17.0, 10.0),
    "M24": (24.0, 36.0, 24.0, 19.0, 12.0),
    "M30": (30.0, 45.0, 30.0, 22.0, 15.5),
    "M36": (36.0, 54.0, 36.0, 27.0, 19.0),
    "M42": (42.0, 63.0, 42.0, 32.0, 24.0),
    "M48": (48.0, 72.0, 48.0, 36.0, 28.0),
    "M56": (56.0, 84.0, 56.0, 41.0, 34.0),
    "M64": (64.0, 96.0, 64.0, 46.0, 38.0),
}
# material choice: (STEVE material library id, appearance colour)
MATERIALS = {
    "steel": ("steel-generic", "#2b2d30"),        # property class 8.8 / 10.9 / 12.9, black oxide finish
    "stainless-a2": ("stainless-304", "#c9ccd0"),  # ISO 3506-1 A2-70
    "stainless-a4": ("stainless-316", "#c9ccd0"),  # ISO 3506-1 A4-70 / A4-80
}

d, dk, k, s, t = DIMENSIONS[size]
material_id, colour = MATERIALS[material]

model = Model()
with model.sketch("head_sketch", on="XY", name="Head") as sk:
    sk.circle("head_circle", (0, 0), dk / 2)
model.extrude("head", "head_sketch", distance=k, name="Head")
with model.sketch("shank_sketch", on="XY", name="Shank") as sk:
    sk.circle("shank_circle", (0, 0), d / 2)
model.extrude("shank", "shank_sketch", distance=-length, name="Shank")
model.plane("head_top", on="XY", offset=k, name="Head top")
with model.sketch("socket_sketch", on="head_top", name="Hexagon socket") as sk:
    sk.polygon("hex", (0, 0), s / 2, 6, inscribed=False)
model.extrude("socket", "socket_sketch", distance=-t, op="cut", name="Socket")
model.material(material_id, color=colour)
result = model.result()