Threads

Overview

Engineering reference data for Threads in miscellaneous.

Key Formulas

Unit Conversion

$y = x \cdot k$

Multiply by conversion factor.

Linear Interpolation

$y = y_1 + \frac{(x - x_1)(y_2 - y_1)}{x_2 - x_1}$

Estimate between two known points.

Percentage

$p = \frac{\text{part}}{\text{whole}} \times 100\%$

Part as fraction of whole.

Variables

Symbol	Description	Unit
$x$	Input value	—
$y$	Output value	—
$k$	Conversion factor	—

Thread Standards Reference

Key Terminology

• NPT (National Pipe Thread): A U.S. standard for tapered threads on pipes and fittings, creating a seal through thread deformation and often requiring a sealant.
• BSP (British Standard Pipe): The British standard for pipe threads. Includes BSPT (tapered, sealant required) and BSPP (parallel, typically requires an O-ring or washer for sealing).
• Unified Thread (UN): A standard for inch-based fastener threads. UNC is the coarse series, offering easier assembly. UNF is the fine series, providing higher tensile strength.
• ACME Thread: A trapezoidal thread form used for power screws (e.g., lead screws, vises) due to its strength and ease of manufacturing.
• Metric Thread: Designated by an "M" followed by the nominal diameter and pitch in millimeters (e.g., M10x1.5).

References

• Original Source