Source: https://guthlabs.ai/docs/instruments/shaft-power-torque-speed-calculator/

instrument / verified-clean

# Shaft Power-Torque-Speed Calculator

The current ledger marks this instrument verified clean within the source-bound verification corpus.

Status: **VERIFIED_CLEAN**Lifecycle: **verified-clean**

## Inspectable records

[01**Overview**Purpose and lifecycle](<https://guthlabs.ai/docs/instruments/shaft-power-torque-speed-calculator/>)[02**Mechanism**Method and assumptions](<https://guthlabs.ai/docs/instruments/shaft-power-torque-speed-calculator/mechanism/>)[03**Implementation**Binding and validation](<https://guthlabs.ai/docs/instruments/shaft-power-torque-speed-calculator/implementation/>)[04**Qualification**Evidence and errata](<https://guthlabs.ai/docs/instruments/shaft-power-torque-speed-calculator/qualification/>)

## Ledger state

The current ledger marks this instrument verified clean within the source-bound verification corpus.

**Area**: Mechanical, Civil & Structural Engineering — Statics/Dynamics, Strength of Materials, Machine Design, Civil, HVAC, Vibration

**Tranche**: tranche-4

**Evidence ID**: t4-070

**Ledger rows**: 1

No ledger note is attached.

## Review findings

The formula P = Tω = 2πNT/60 is standard and correct under the stated units. NEEDS_REVIEW is required because the ω output unit is not explicitly declared and the input mode ('P or T') does not specify behavior when both or neither are provided. The blank honest_label does not create a mathematical overclaim, but the user-facing label should state the input mode, output units, and zero-speed limitation.

### Formula and scope findings

No additional record

### Unit assumptions

- N is rotational speed in revolutions per minute (rpm).

- T is torque in newton-metres (N·m).

- P is power in watts (W).

- ω is assumed to be angular velocity in radians per second (rad/s), although the output unit is not explicitly stated.

- The formula assumes consistent signed quantities; if magnitudes are intended, direction/sign conventions must be specified.

## Boundary hardening

**BREAK_CLAIMED** · SELF_FLAGGED

A nonzero power input at zero rpm produces a zero denominator when torque is calculated, so the instrument must reject the input or report torque as undefined rather than returning a finite value.

## Errata and corrections

No applied erratum is attached to this unique-name record.

## Inspectable example

4 review vectors are recorded. One source-bound sample is shown below.

````
{
  "inputs": {
    "T_Nm": 50,
    "N_rpm": 1800
  },
  "expected_outputs": {
    "omega_rad_per_s": 188.49555921538757,
    "P_W": 9424.77796076938,
    "T_Nm": 50
  },
  "working": "ω = 2πN/60 = 2π(1800)/60 = 60π = 188.49555921538757 rad/s. P = Tω = 50 × 188.49555921538757 = 9424.77796076938 W."
}
````

## Related workflows

[Motor & Drivetrain Benchshaft point](<https://guthlabs.ai/docs/instrument-workflows/motor-drive/>)

## Sources and evidence

These pointers bind the page to evidence. They do not grant authority or collapse verification into deployment.

- `VERIFIED_LEDGER.json · VERIFIED_CLEAN`

- `evidence-tranche4/tranche4-results.json`

- `BOUNDARY_HAZARD_CATALOG.json`