Belt splicing unit converter
Convert the units splice manuals mix: PIW, kgf/cm², psi, bar, °F — and temperature differences.
Result
How it works
Splice manuals and press data sheets mix metric and US units: belt ratings in PIW, press pressure in kgf/cm², psi or bar, and cure temperatures in °F. Errors creep in, especially with temperature tolerances.
A temperature difference converts with the factor 5/9 only. Subtracting 32 is correct for a temperature, but wrong for a tolerance or a rise — one manual prints ±18 °F as −7.7 °C instead of ±10 °C.
Formula
1 PIW (lbf/in) = 0.17513 N/mm 1 kgf/cm² = 0.0980665 MPa 1 psi = 0.0068948 MPa; 1 bar = 0.1 MPa °C = (°F − 32) × 5/9 (temperature) K = Δ°F × 5/9 (difference: no −32)
| Symbol | Meaning | Unit |
|---|---|---|
| PIW | Pounds-force per inch of belt width | lbf/in |
| kgf/cm² | Kilogram-force per square centimetre | — |
| psi | Pounds-force per square inch | — |
| Δ°F | Temperature difference or tolerance in °F | — |
Worked example
Inputs: Belt rating = 250 PIW; Pressure = 7 kgf/cm²; Pressure = 130 psi; Pressure = 10 bar; Temperature = 325 °F; Temperature difference = 18 Δ°F.
- 250 PIW × 0.17513 = 43.78 N/mm
- 7 kgf/cm² × 0.0980665 = 0.686 MPa
- 130 psi × 0.0068948 = 0.896 MPa
- (325 − 32) × 5/9 = 162.8 °C
- ±18 °F × 5/9 = ±10 °C (not −7.7 °C)
Assumptions and limits
- Exact factors: 1 lbf = 4.4482216 N, 1 in = 25.4 mm, 1 kgf = 9.80665 N.
- A PIW rating may be a working tension; EP ratings are breaking strength. Convert units, but do not treat one rating basis as the other.
Screening estimate, not a design approval. Verify measured inputs, current standards, manufacturer limits and site procedures before purchasing, cutting or installation. Isolate and lock out equipment before any hands-on measurement.
Questions
How many N/mm is 250 PIW?
43.78 N/mm.
Is 7 kgf/cm² the same as 7 bar?
Almost: 7 kgf/cm² = 0.686 MPa = 6.86 bar.
Source notes
- Exact SI definitions of the pound-force, inch and kilogram-force. Conversion errors noted in the source review of splicing manuals (ContiTech fabric splice manual 2015, temperature tolerances).
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