Effort Required in Lifting Load with Trapezoidal Threaded Screw Calculator

Effort Formula:

\[ P_{li} = W \times \left( \frac{\mu \times \sec(0.2618) + \tan(\alpha)}{1 - \mu \times \sec(0.2618) \times \tan(\alpha)} \right) \]

Effort in Lifting Load (P_li): N

Definition: This is the force required to overcome resistance when lifting a load using a trapezoidal threaded screw.

Purpose: It helps mechanical engineers and designers determine the torque needed for screw jacks, vises, and other lifting mechanisms.

The calculator uses the formula:

\[ P_{li} = W \times \left( \frac{\mu \times \sec(15°) + \tan(\alpha)}{1 - \mu \times \sec(15°) \times \tan(\alpha)} \right) \]

Where:

Details: Proper calculation ensures screw mechanisms are designed with adequate power and safety margins.

Tips: Enter the load in newtons, friction coefficient (default 0.15 ±5%), and helix angle in radians (default 0.0785 rad ≈ 4.5°).

Q1: Why is there a sec(15°) term?
A: This accounts for the standard 30° included angle of trapezoidal threads (half-angle is 15°).

Q2: What's a typical coefficient of friction?
A: For steel screws and nuts, μ ≈ 0.15±5%, but this varies with lubrication and materials.

Q3: How do I convert helix angle from degrees to radians?
A: Multiply degrees by π/180 (e.g., 4.5° × π/180 ≈ 0.0785 rad).

Q4: Does this include safety factors?
A: No, apply appropriate safety factors after calculating the theoretical effort.

Q5: How does this differ from square thread calculations?
A: Square threads don't have the sec(15°) term since their thread angle is 0°.