MechKit
The Journal
Understanding Bolt Torque
Torque is only a proxy for the bolt tension that actually clamps a joint. Learn the T = K F d equation, why lubrication changes everything, and how to set preload.
Gear Ratios Explained
Count the teeth and you can predict output speed and torque exactly. This guide covers the ratio formula, a worked 3:1 example, gear trains, idlers, and the speed-torque trade-off.
Choosing the Right Fastener
Bolt, screw, or stud? Which property class, thread, head, and material? A practical walk through every decision that separates a joint that lasts from one that strips or corrodes.
Reading Engineering Tolerances
No part is ever made to an exact size, so drawings specify a range. Understand limits, deviations, clearance and interference fits, ISO IT grades, and why tighter tolerances cost more.
Belt vs Chain Drives
Belts grip by friction, chains engage positively, and that single difference decides which drive suits your machine. Compare efficiency, slip, noise, and maintenance in a side-by-side table.
Metal Density and Weight
Weight equals volume times density. Use a density table for common metals and a worked steel-bar example to estimate part mass before cutting anything, and see why it matters.
Hydraulic Systems Basics
A confined fluid multiplies force through F = P times A. Learn Pascal's principle, why cylinders push harder than they pull, how flow sets speed, and the components that make it work.
Sizing a Job From Five Numbers
Most small mechanical jobs turn on a handful of figures, and having them before you start is the difference between one trip to the supplier and three.
What a Torque Wrench Cannot Tell You
A torque wrench measures torque. It does not measure the thing you actually care about, which is how hard the bolt is clamping. The gap between those two is…
Tolerances, Fits, and Why Stack-Up Passes Inspection
A drawing dimension without a tolerance is an aspiration. Nothing is made to an exact size, and the tolerance is where the designer says how much the real…
Work Out the Weight Before You Lift It
Steel is heavier than people estimate and aluminium is lighter, and both errors cause the same problem: someone commits to lifting, mounting or shipping…
Gear and Belt Ratios: The Same Trade, Two Ways
Gears and belts do the same job by different means: trade speed for torque, or the reverse. The arithmetic is the same shape in both, and the differences…