"""Hex head screw, inch series: hex cap screws to ASME B18.2.1 (1/4 to 1/2 in) and hex head machine screws to
ASME B18.6.3 (#2 to #10), UNC and UNF, any length.

Envelope model for assemblies: hexagon head (width across flats F, height H; corners and washer face not chamfered)
and a plain shank at the basic major diameter D of ASME B1.1 (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` (inches) is the nominal length
under the head. The model is in millimetres (1 in = 25.4 mm).
"""
from steve import Model

size = "1/4-20"  # Thread (Unified, ASME B1.1)
length = 1.0  # in Nominal length under the head
material = "steel"  # Material

# Thread designation: nominal size
THREADS = {
    "#0-80": "#0", "#1-64": "#1", "#1-72": "#1", "#2-56": "#2", "#2-64": "#2", "#3-48": "#3", "#3-56": "#3",
    "#4-40": "#4", "#4-48": "#4", "#5-40": "#5", "#5-44": "#5", "#6-32": "#6", "#6-40": "#6", "#8-32": "#8",
    "#8-36": "#8", "#10-24": "#10", "#10-32": "#10", "1/4-20": "1/4", "1/4-28": "1/4", "5/16-18": "5/16",
    "5/16-24": "5/16", "3/8-16": "3/8", "3/8-24": "3/8", "7/16-14": "7/16", "7/16-20": "7/16", "1/2-13": "1/2",
    "1/2-20": "1/2",
}
# Inches. D: ASME B1.1-1989 (R2001) basic major diameter, as reproduced at
# https://www.engineersedge.com/screw_threads_chart.htm ("Major Diameter Basic").
# #2 to #10: ASME B18.6.3-2013 Table 29 (plain and slotted hex head machine screws, regular head), F max and H max
# (the table has no basic column), as reproduced in Tanner's catalogue p. 72 (ASME B18.6.3-2002 table, same values)
# https://www.tannerbolt.com/media/akeneo_connector/Machinehexhds.pdf and at https://torqbolt.com/asme-b18-6-3-plain-and-slotted-hexagon-head-machine-screws-dimensions-standards-specifications
# 1/4 to 1/2: ASME B18.2.1-2012 Table 6 (hex cap screws), F basic and H basic, as reproduced at
# https://torqbolt.com/asme-b18-2-1-hex-cap-screws-dimensions-standards-specifications and
# https://www.aftfasteners.com/hex-cap-screws-head-thread-dimensions-performance-mechanical-specs/
# nominal: (D, F, H)
DIMENSIONS = {
    "#2": (0.0860, 0.125, 0.050),
    "#4": (0.1120, 0.188, 0.060),
    "#6": (0.1380, 0.250, 0.093),
    "#8": (0.1640, 0.250, 0.110),
    "#10": (0.1900, 0.312, 0.120),
    "1/4": (0.2500, 0.4375, 0.15625),
    "5/16": (0.3125, 0.500, 0.203125),
    "3/8": (0.3750, 0.5625, 0.234375),
    "7/16": (0.4375, 0.625, 0.28125),
    "1/2": (0.5000, 0.750, 0.3125),
}
# material choice: (STEVE material library id, appearance colour)
MATERIALS = {
    "steel": ("steel-generic", "#b8bcc2"),        # carbon steel, zinc plated
    "stainless-18-8": ("stainless-304", "#c9ccd0"),
    "stainless-316": ("stainless-316", "#c9ccd0"),
}
INCH = 25.4

D, F, H = DIMENSIONS[THREADS[size]]
d = D * INCH
s = F * INCH
k = H * INCH
shank = length * INCH
material_id, colour = MATERIALS[material]

model = Model()
with model.sketch("head_sketch", on="XY", name="Head") as sk:
    sk.polygon("hex", (0, 0), s / 2, 6, inscribed=False)
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=-shank, name="Shank")
model.material(material_id, color=colour)
result = model.result()