Practical Engineering Tools
Practical engineering tools for calculations, checks, conversions, references, generators, and the workflow around them.
Fixed Fastener Formula
Calculate the required positional tolerance for clearance holes in a fixed fastener assembly. Applies the GD&T fixed fastener formula T = H − F to determine tolerance distribution between mating parts.
Bolt Torque Calculator
Find the recommended and maximum install torque for a fastener and the resulting bolt tension (preload), from bolt size, proof strength, and nut factor K. Preliminary (PDR-level) tool.
Tolerance Stack-Up Calculator
Build a manual 1D tolerance stack-up, 2D hole alignment check, or fastener clearance workflow with STEP assembly context, worst-case, RSS, Monte Carlo yield, and contributor impact ranking.
Engineering Copilot
Mechanical engineering copilot for DFM, machining, and manufacturing questions.
Drawing Redliner
AI drawing review: upload a drawing and get structured redline feedback.
GD&T Cheat Sheet
The symbols, datum rules, and feature control frame anatomy on one page. The reference to keep open while you dimension.
Tap and Drill Chart
Drill sizes for every common inch and metric thread, with thread engagement percentages so you can pick a size instead of guessing.
Weld Symbol Chart
Weld symbols and what each one actually asks the shop to do, including the ones people draw wrong most often.
DFM Design Guides
CNC, sheet metal, and injection molding design guides: what each process needs from your part, and what it costs you to ignore.