村头宝 vs Mechanical Engineering Toolkit

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Mechanical Engineering Toolkit is a professional engineering calculator for students, researchers, and practicing engineers. Choose a formula, enter your variables, and get instant results — with calculation steps, formulas, diagrams, and unit conversions shown along the way. Switch between SI and Imperial units anytime, save favorites, and find the right tool fast with recommendations by major. Save your inputs as named projects, and export any result as text, image, CSV or PDF. Categories and tools: Mechanics of Material • Moments of inertia of plane areas • Force-displacement relation of a bar • Torsion formula and angle of twist • Flexure formula of a beam • Transverse shear stress • Deflections and slopes of cantilever and simple beams • Plane stress transformation and Mohr's circle • Principal stresses and planes • Spherical shell and thin-walled pressure vessel stresses • Buckling load of a column • Thermal deformation and stress • Combined loading • Bolted / riveted joints • Fatigue safety factor • Shaft power and torque Statics • Centroid of an area • Resultant of a force system • Beam reactions • 2D truss analysis Machine Design • Helical compression springs • Spur gear geometry and stresses • Shaft fatigue design (DE-Goodman) • Bearing L10 life • Belt and chain drives • Bolt preload / torque-tension • Fillet weld strength • Press / shrink-fit interference • Shaft critical speed (Dunkerley) • Beam natural frequency (five end conditions) • Torsional natural frequency (one or two rotors) Fluids & Thermal • Reynolds number and flow regime • Pipe pressure drop (Darcy-Weisbach with Colebrook) • Pump and fan power • Composite wall conduction • Fin efficiency • Heat exchanger sizing by LMTD Theory of Elasticity • Constitutive relation of linear elastic material • Stress/strain of linear elastic material Composite Material • Lamina and laminate stress/strain • Lamina engineering constants • Laminate plane and 3D properties • Rule of mixtures • Failure criteria (Tsai-Hill, Tsai-Wu) Reference Tables • Drill & tap chart (metric and imperial thread series) • ISO 286 fits & tolerances • Standard sections (AISC W, IPE, HEB) • Unit converter No account required. Works offline. Available in English, Chinese, German, French, and Japanese.