What is the lead angle?

The lead angle (also called helix angle) is the angle between the helix formed by a screw thread or spiral groove and a plane perpendicular to the screw axis. A higher lead angle means a steeper spiral, which increases the effective path length of material. Values typically range from 1° for fine-pitch screws to 45° or more for fast-lead power screws.

Why does the lead angle affect weight?

In spiral-cut or threaded components, material follows a helical path rather than a straight axial path. The effective length along the helix is longer than the axial length by a factor of 1/cos(lead angle). This tool applies that correction so weight estimates account for the actual material path.

What density is used for lead?

The default density is 11.34 g/cm³, which is the density of pure lead (Pb). For common lead alloys, you can enter a custom value — for example, 11.0 g/cm³ for lead-antimony alloy, or 10.66 g/cm³ for 50/50 lead-tin solder.

What geometries are supported?

Three cross-section types are supported: solid cylinder (round bar or rod), hollow cylinder (lead pipe or tube), and rectangular bar (flat or square lead stock). Each uses the correct area formula before applying the lead-angle length correction.

What units are supported?

Metric (mm for cross-section dimensions, m for length, output in kg) and imperial (inches for dimensions, feet for length, output in lb). Toggle at any time — inputs are not cleared when switching.

Is a zero lead angle valid?

Yes. At 0° the helix correction factor is 1.0 (cos 0° = 1), so the calculator simply returns the straight geometric weight with no correction applied. This is useful for computing the weight of un-threaded lead stock.

Lead Angle Weight Calculator

Name: Lead Angle Weight Calculator
Availability: InStock
Author: Nham Vu

Enter the geometry and lead angle of a lead (Pb) workpiece to calculate its corrected weight in engineering applications.

Lead Object Dimensions

Unit system:

Cross-section shape

Diameter (mm)

Axial length (m)

Lead angle (degrees, 0–89)

Density (g/cm³ — default 11.34 for pure Pb)

Geometry Diagram

Enter dimensions and click Calculate

Summary