Source: https://guthlabs.ai/docs/instruments/clutch-brake-torque-capacity-calculator/implementation/

instrument implementation / implementation-contract

# Clutch/Brake Torque Capacity Calculator implementation

A source-bound implementation contract for Clutch/Brake Torque Capacity Calculator; deployment and executable qualification remain separate.

Status: **VERIFIED_WITH_ERRATA**Lifecycle: **implementation-contract**

## Binding contract

This record describes what an executable surface must bind and validate. It does not claim that a public calculator, package, or production route is deployed.

**Record owner**: Guth Instruments

**Lifecycle**: verified-with-binding-errata

**Evidence ID**: t5-084

**Effect**: Computation or source lookup only

## Input and validation requirements

The uniform-pressure formula becomes undefined when ro=ri because its denominator ro^2-ri^2 is zero. The instrument should reject that geometry rather than return a numeric torque. Additional hazards are the physically invalid n=0 boundary, the unspecified branch-selection criterion, and the sign convention for axial force and torque.

## Required corrections

````
[
  {
    "vector": 3,
    "field": "T_Nm",
    "wrong": 506.25,
    "correct": 56.25,
    "cause": "output contradicts her own working, which computes (and self-corrects to) 56.25"
  }
]
````

## Inspectable interface fixture

The sample below is evidence for interface and validation tests, not a production implementation.

````
{
  "inputs": {
    "mu": 0.3,
    "F_N": 4000,
    "ro_m": 0.15,
    "ri_m": 0.08,
    "n_friction_surfaces": 2,
    "wear_model": "uniform_wear"
  },
  "expected_outputs": {
    "T_Nm": 276
  },
  "working": "r_eff=(ro+ri)/2=(0.15+0.08)/2=0.23/2=0.115 m. T=n·μ·F·r_eff=2·0.3·4000·0.115=0.6·4000·0.115=2400·0.115=276 N·m."
}
````

## Other records

[01**Overview**](<https://guthlabs.ai/docs/instruments/clutch-brake-torque-capacity-calculator/>)[02**Mechanism**](<https://guthlabs.ai/docs/instruments/clutch-brake-torque-capacity-calculator/mechanism/>)[04**Qualification**](<https://guthlabs.ai/docs/instruments/clutch-brake-torque-capacity-calculator/qualification/>)

## Sources and evidence

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

- `VERIFIED_LEDGER.json`

- `evidence-tranche5/tranche5-results.json`

- `tranche errata record`