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Engineering Guides
Free, in-depth guides written around the same formula, materials, and reference data you can browse in EngiRef. Every guide is free, no account required.
Choosing Engineering Materials 101: How to Read Properties and Pick the Right One
A beginner's guide to selecting engineering materials: what strength, stiffness, ductility, and hardness actually mean, and how to match properties to a job.
Understanding Safety Factors: What They Cover and How to Choose One
A practical guide to factors of safety in engineering: what a safety factor really accounts for, how design and yield factors differ, and how to pick a value.
How to Select the Right Bolt Grade
A practical guide to bolt grade selection: what metric property classes and SAE grades mean, how proof load and tensile strength differ, and how to avoid mismatches.
SI vs Imperial: The Unit Mistakes That Wreck Calculations
A guide to the unit-system pitfalls that cause engineering errors: pounds mass versus pounds force, the gc factor, mixed prefixes, and how to check units.
How to Read Pipe Schedules: NPS, Schedule Numbers, and Wall Thickness
Pipe schedules explained: what nominal pipe size and schedule numbers mean, why the stated size is not the real diameter, and how wall thickness works.
Selecting Wire Gauge: Current Capacity and Voltage Drop Explained
How to choose wire gauge (AWG): how the numbering works backward, what ampacity means, and why voltage drop often decides the size on long runs.
Stress and Strain Basics: The Foundation of Mechanical Design
An introduction to stress and strain: what each one means, how they relate through the elastic modulus, and how the stress-strain curve predicts failure.
How to Read a Material Datasheet Without Getting Misled
How to interpret a material datasheet: which properties matter, how typical and minimum values differ, and the fine print that changes the numbers.
Bending Stress and Section Modulus Explained
How bending stress develops inside a loaded beam, why section modulus matters more than raw area, and how to size a beam against yield.
Torsion and Shafts Explained: Torque, Shear Stress, and Twist
How torque produces shear stress and twist in a shaft, the formulas behind both, and why hollow and larger-diameter shafts resist torsion so much better.