Engineering & Materials
Every engineering & materials calculator on CalcEngines — unit converters, derived indices and interpretive tools, each with its formula, a worked example and the reference intervals it is judged against.
4 calculators in this section
- Density and Specific Gravity ConverterTwelve density units derived from exact definitions — including the pound per US gallon and the pound per imperial gallon, which are 20.1% apart — plus specific gravity on the 60/60 °F, 20/4 °C and 20/20 °C conventions with the difference between them shown, API gravity, and all four published Baumé constants rather than one. Water's density comes from Tanaka's formula, because it is not 1.000.
- Hardness Scale Converter (HV, HB, HRC, HRB, Knoop)Vickers, Brinell, Rockwell C and B and Knoop for non-austenitic steel — and a refusal for the other six material groups ASTM E140 gives separate tables to, because there is no universal hardness conversion. Each scale's valid range is enforced and the blank outside it is the answer. Shore A and Shore D do not convert to metal scales at all.
- Surface Roughness Converter (Ra, µin, CLA, RMS, Rz, N Grade)Ra in micrometres and microinches, CLA, AA, RMS and the ISO N grades — with a plain account of which of those conversions are exact and which are guesses. Ra to CLA is an identity. Ra to Rq depends on the profile shape. Ra to Rz has no valid conversion at all, and every chart on the web prints one anyway.
- Viscosity Converter (Dynamic and Kinematic)Dynamic and kinematic viscosity are different quantities and ν = µ / ρ, so converting between them needs the fluid's density — which is why water is 1.0016 cP and 1.0034 cSt and neither is exactly 1. Sixteen units plus Saybolt from the real ASTM D2161 equation, ISO 3448 and SAE J300 explained rather than conflated, and ASTM D341 for the one temperature conversion that can be done honestly.