SSU ↔ cSt Viscosity Converter
Convert Saybolt Universal Seconds to centistokes (and back) for lube-oil specs.
Legacy US pump curves and old lube specs quote SSU; ISO VG grades are cSt at 40 °C. 200 SSU ≈ 43 cSt ≈ ISO VG46.
Formula
SSU ↔ cSt Viscosity Converter is a free ssu to cst for process, mechanical and water engineers — instant, accurate and 100% client-side, with the governing formula and reference shown next to the result so the number can be defended, not just quoted.
About SSU ↔ cSt Viscosity Converter
Convert Saybolt Universal Seconds to centistokes (and back) for lube-oil specs. The calculation implements ν(cSt) = 0.226·t − 195/t (t ≤ 100 SSU); 0.220·t − 135/t (t > 100 SSU) (ASTM D2161 — conversion to Saybolt viscosity). Legacy US pump curves and old lube specs quote SSU; ISO VG grades are cSt at 40 °C. 200 SSU ≈ 43 cSt ≈ ISO VG46.
How to use SSU ↔ cSt Viscosity Converter
- 1Enter Saybolt Universal Seconds in SSU.
- 2Read Kinematic viscosity instantly — no submit button needed.
Why use SSU ↔ cSt Viscosity Converter?
- ✓Implements the standard formula — ν(cSt) = 0.226·t − 195/t (t ≤ 100 SSU); 0.220·t − 135/t (t > 100 SSU)
- ✓Reference cited on-page: ASTM D2161 — conversion to Saybolt viscosity
- ✓Live worked example: the substitution recomputes from your numbers
- ✓Runs entirely in your browser — nothing uploaded, free forever
Frequently asked questions
What formula does the SSU ↔ cSt Viscosity Converter use?+
It computes ν(cSt) = 0.226·t − 195/t (t ≤ 100 SSU); 0.220·t − 135/t (t > 100 SSU), per ASTM D2161 — conversion to Saybolt viscosity. The formula is displayed under the result along with a worked example substituted with your own inputs.
What should I keep in mind when using this calculator?+
Legacy US pump curves and old lube specs quote SSU; ISO VG grades are cSt at 40 °C. 200 SSU ≈ 43 cSt ≈ ISO VG46.
Does this work for any fluid?+
Yes — density and viscosity are inputs (with common fluids suggested in the field hints), so the same physics applies to water, oils, gases and process fluids. Compute always runs in SI internally, so unit mix-ups can't corrupt the result.
Is the SSU ↔ cSt Viscosity Converter free to use?+
Yes — completely free, no sign-up, no limits. It runs client-side in your browser, so inputs stay private and results are instant even on slow connections.
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