Source: https://guthlabs.ai/docs/instruments/press-shrink-fit-interference-calculator/implementation/

instrument implementation / implementation-contract

# Press/Shrink Fit Interference Calculator implementation

A source-bound implementation contract for Press/Shrink Fit Interference Calculator; deployment and executable qualification remain separate.

Status: **VERIFIED_CLEAN**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-clean

**Evidence ID**: t5-064

**Effect**: Computation or source lookup only

## Input and validation requirements

The specification leaves torque underdetermined because friction coefficient and contact length are absent, and it does not define whether interference is diametral or radial. The formula also becomes undefined at ro=d and produces nonphysical continuation results for ro<d unless the instrument rejects those inputs.

## Required corrections

No binding erratum is attached to this unique-name record. Implementers must still preserve the declared units, domain, and failure behavior.

## Inspectable interface fixture

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

````
{
  "inputs": {
    "d": 50,
    "ro": 100,
    "delta": 0.1,
    "E": 210000,
    "nu": 0.3,
    "units": "d, ro, delta in mm; E in MPa"
  },
  "expected_outputs": {
    "contact_pressure_p": 213.559322,
    "hoop_stress_hub": 355.932203,
    "transmittable_torque": null
  },
  "working": "ro²=100²=10000; d²=50²=2500; ratio=(ro²+d²)/(ro²-d²)=(10000+2500)/(10000-2500)=12500/7500=5/3=1.6666667. Denominator=d(ratio+ν)=50(1.6666667+0.3)=50(1.9666667)=98.3333333. Numerator=Eδ=210000×0.1=21000 MPa·mm. p=21000/98.3333333=213.559322 MPa. Hoop stress=p×ratio=213.559322×1.6666667=355.932203 MPa. Torque is undefined because no torque formula or friction data are supplied."
}
````

## Other records

[01**Overview**](<https://guthlabs.ai/docs/instruments/press-shrink-fit-interference-calculator/>)[02**Mechanism**](<https://guthlabs.ai/docs/instruments/press-shrink-fit-interference-calculator/mechanism/>)[04**Qualification**](<https://guthlabs.ai/docs/instruments/press-shrink-fit-interference-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`