Adding ISOThread and UNC Thread

app/models/unc_thread.py

@@ -0,0 +1,24 @@
+import enum
+
+from sqlalchemy import Enum, Float, Integer, String
+from sqlalchemy.orm import Mapped, mapped_column
+
+from app.core.database import Base
+
+
+class UncSeries(str, enum.Enum):
+    UNC = "UNC"
+    UNF = "UNF"
+    UNEF = "UNEF"
+    UN = "UN"
+    UNS = "UNS"
+
+
+class UncThread(Base):
+    __tablename__ = "unc_threads"
+
+    id: Mapped[int] = mapped_column(Integer, primary_key=True)
+    diameter_fraction: Mapped[str] = mapped_column(String(16), nullable=False)
+    tpi: Mapped[int] = mapped_column(Integer, nullable=False)
+    series: Mapped[UncSeries] = mapped_column(Enum(UncSeries), nullable=False)
+    depth_in: Mapped[float | None] = mapped_column(Float, nullable=True, default=None)