Convert Microinch to Cable
Convert microinches to cables instantly. 1 microinch = 1.37149e-10 cable — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Cable to Microinch converter for the reverse conversion.
Units explained
Microinch
A microinch is an Imperial unit of length equal to one millionth of an inch (2.54×10⁻⁸ m). It is used almost exclusively in surface-finish specifications for precision machining and optical components.
The microinch is derived from the inch using the SI-style prefix micro- to denote one millionth. Standardised through the 1959 International Yard and Pound Agreement, which fixed the inch at exactly 25.4 mm.
Microinches express surface roughness (Ra values) in US-based precision manufacturing — typical machined surfaces are 16–125 µin. Optical components and bearing races are often specified to 1–4 µin Ra.
Used in US precision-manufacturing literature throughout the 20th century; value became exact in 1959 when the inch was fixed at 25.4 mm via the International Yard and Pound Agreement.
Cable
A cable is a nautical unit of length equal to one tenth of a nautical mile (exactly 185.2 m). It is used in maritime navigation for short-distance descriptions.
The cable derives from the historical length of a ship's anchor cable. Standardised at one tenth of an international nautical mile in 1929.
Cables are used in modern maritime navigation when describing short distances between vessels, anchoring depths, and harbor manoeuvres. Common in naval and yachting contexts.
Standardised at 1/10 nautical mile by the International Hydrographic Organization in 1929.
Microinch to Cable conversion formula
The relationship between microinches and cables:
To convert microinches to cables, multiply the value in microinches by 1.37149e-10. To reverse, multiply cables by 7.291339e+9.
How to use this converter
Type a value into the calculator. The result in cables updates as you type. Tap a quick value, copy the result with one click, or use the swap arrow to jump straight to the Cable to Microinch converter for the reverse direction.
Step-by-step: convert microinches to cables
- Write down the value in microinches (µin).
- Multiply that value by the factor 1.37149e-10.
- The product is the equivalent value in cables (cable).
- To reverse, multiply the cable value by 7.291339e+9.
Worked examples
Example 1 — Convert 1 µin to cable:
1 × 1.37149e-10 = 1.37149e-10 cable
Example 2 — Convert 100 µin to cable:
100 × 1.37149e-10 = 1.37149e-8 cable
Real-world example — Molecular dimensions
The diameter of small molecular structures (around 2 microinches) is often converted into related sub-micron units when comparing measurements across different microscopy techniques or imaging modalities.
2 µin × 1.37149e-10 = 2.742981e-10 cable
Real-world example — Wavelengths across the spectrum
Optical and atomic-scale phenomena are routinely cross-converted between sub-micron units. A photon of wavelength 800 microinches can be re-expressed in cables for direct comparison with another instrument's calibration data sheet.
800 µin × 1.37149e-10 = 1.097192e-7 cable
Microinch to Cable conversion table
Standard reference values for converting microinches to cables:
| Microinch [µin] | Cable [cable] |
|---|---|
| 0.01 | 1.37149e-12 |
| 0.1 | 1.37149e-11 |
| 1 | 1.37149e-10 |
| 2 | 2.742981e-10 |
| 3 | 4.114471e-10 |
| 4 | 5.485961e-10 |
| 5 | 6.857451e-10 |
| 10 | 1.37149e-9 |
| 20 | 2.742981e-9 |
| 30 | 4.114471e-9 |
| 40 | 5.485961e-9 |
| 50 | 6.857451e-9 |
| 100 | 1.37149e-8 |
| 500 | 6.857451e-8 |
| 1000 | 1.37149e-7 |
Frequently asked questions
How many cables is 1 microinch?
How do I convert microinches to cables?
How do I convert cables back to microinches?
How many cables is 100 microinches?
Popular length unit conversions
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Metric / SI (4 units)
Imperial / US Customary (26 units)
Sources & references
Conversion factor (1 µin = 1.37149e-10 cable) verified against the following authoritative sources:
- BIPM — The International System of Units (SI Brochure 9th ed.)
Official BIPM publication defining the seven SI base units (including the meter) and the rules for their use. The global authority on units of measurement.
- NIST — Guide to the SI
US National Institute of Standards and Technology reference covering the SI base and derived units with definitions and usage rules for US technical practice.
- NIST Special Publication 811 — Guide for the Use of the International System of Units
Detailed NIST guide covering exact conversion factors between SI and US customary units along with formatting and rounding conventions.
- NIST — Refinement of values for the yard and pound (Federal Register 1959)
The treaty (signed by US
- International Astronomical Union — System of Astronomical Constants
The IAU defines astronomical units including the AU (149597870700 m exactly) light-year and parsec used in astronomy and astrophysics.