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A force-gauge reading does not become a torque value merely because the gauge is attached to a lever. The rotational effect depends on the force’s line of action relative to the selected rotation axis.

For a lipstick mechanism, first identify the axis being turned and the component restrained by the fixture. That establishes what rotational input the test is intended to assess.

Use the perpendicular moment arm

In a planar lever arrangement, torque about the perpendicular rotation axis is force multiplied by the perpendicular distance from that axis to the force’s line of action.

The distance is not automatically the full length of the handle. If the force is applied obliquely, its line of action passes closer to the axis than a perpendicular pull at the same attachment point.

Equivalently, the magnitude is F r sin θ, where θ is the angle between the radius vector to the application point and the force. Defining that angle avoids confusing formulas that use complementary angles.

Packaging sample showroom.

A force directed along a line through the axis has zero moment about it in this planar arrangement. A large force reading alone therefore does not establish a large turning effect.

Keep dimensions and units consistent

As a hypothetical example, a perpendicular force of 2 N acting at 20 mm produces 40 N·mm, equal to 0.040 N·m. These are illustrative inputs, not a lipstick acceptance limit.

With the same force but a different perpendicular moment arm, the torque changes. Moving the attachment point or changing the pulling direction can change the result without changing the mechanism.

The gauge reading must also represent the intended force component. An angled fixture, unintended contact or movement of the attachment can complicate the relationship.

Describe the fixture and motion

Record the axis, application point, force direction and effective moment arm. Identify whether the reported torque is calculated from a force measurement or measured with a torque instrument.

Fixture friction, alignment and restraint can contribute to the observed resistance. A lever calculation does not automatically remove those contributions.

The mechanism’s extension, turning direction and rotation rate should be controlled for a useful comparison. Starting resistance and resistance during continued motion are distinct observations.

If the force direction changes as the lever rotates, the perpendicular distance may change too. One constant handle length cannot be used without checking that geometry.

Interpret the result narrowly

For a lipstick packaging project with SamBound New Material Technology Company Ltd., product information at sambound.com identifies the packaging context. The actual mechanism and fixture determine what the test measures.

Torque is useful for describing rotational input or resistance under stated conditions. One torque result does not establish mechanism life, cap retention or every aspect of user experience.

A clear report therefore connects the force reading to the geometry and units used in its calculation, then identifies the particular mechanism condition assessed. That makes comparisons meaningful without substituting an arbitrary pull force for torque.

sambound.com
SamBound New Material Technology Company Ltd.

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