About MechKit

Mechanical work runs on a handful of relationships repeated in a thousand forms: torque set against clamp force, one gear’s teeth against another’s, pressure acting over an area, weight following from volume and density. The concepts aren’t hard, but the arithmetic in the middle — the stress area of an M10 thread, the output speed after a 3:1 reduction, the extend force of a 63 mm cylinder at 160 bar — is exactly where a job stalls. MechKit is built to take that arithmetic off your bench so you can get back to the work.

Rather than long essays you have to wade through, the site is a set of small, single-purpose calculators, each aimed at one real task. The Bolt Torque Calculator turns a size, grade, and lubrication condition into a tightening torque and clamp load. The Gear Ratio & Output Speed Calculator works out ratio, output speed, and torque for a gear pair. The Belt & Pulley Calculator gives driven speed, belt speed, and belt length from pulley sizes and centre distance. The Material Weight Calculator estimates the mass of a bar, plate, or tube from its volume and density. The Hydraulic Cylinder Force Calculator converts bore, rod, and pressure into extend and retract force, and the Thread & Fastener Size Reference looks up pitch, tap-drill size, and stress area for standard metric threads.

Alongside the calculators, the blog and learnsection explain the reasoning the tools rest on — why torque is only a proxy for the tension you actually want, how a gear train trades speed for torque, what an engineering tolerance really promises, and why a hydraulic ram can push so much harder than it looks. Every explanation is written from scratch and worked through with real numbers.

A few things worth stating plainly. MechKit is independent and not affiliated with any tool maker, fastener supplier, or standards body. It is supported by advertising, which is how the tools stay free with no account required. The calculators are planning and checking aids: they apply standard formulas and round for readability, but for anything that carries a real load — a structural joint, a lifting rig, a pressure system — you should confirm the result against the manufacturer’s specification and, where it matters, a qualified engineer. If a tool looks wrong, or there’s a calculator you wish existed, the contact page is the place to tell us.