Design Calculations & Reference

Tolerances, fits, thread and drill tables, torque, and the calculations behind a spec.

MAWP vs Design vs Operating Pressure

MAWP is the highest pressure a vessel may see at the top, at a stated temperature.

October 22, 2026

How to Calculate Belt Length for 2 or 3 Pulleys

Open belt length is L = 2C + pi(D+d)/2 + (D-d)^2/4C. The crossed-belt and three-pulley methods, which length a belt number uses, and centre distance.

October 19, 2026

What Is Power Factor? kW vs kVA in Plain Words

Power factor is the ratio of useful power (kW) to total apparent power (kVA). Why motors and drives lower it, how correction works, and why bills care.

October 7, 2026

ISO Tolerances and Fits: Reading H7/g6

Decoding the ISO limits-and-fits system: how letter codes define tolerance zone position and IT grades define width, and why H7/g6 creates a precise running.

August 11, 2026

Bolt Torque and Preload: Where the Numbers Come From

Torque is only a proxy for bolt preload. Understand the friction mechanics, the torque-tension relationship, and advanced tightening methods to ensure reliable.

August 11, 2026

Motor Frame Sizes and Mounting Designations

NEMA and IEC motor frame numbers encode shaft height, mounting dimensions, and flange type.

August 11, 2026

Surface Roughness: Ra, Rz and What to Specify

Learn how Ra and Rz differ, why identical Ra values can yield opposite sealing performance, and which roughness levels suit common machining processes.

August 11, 2026

Wire Gauge, Ampacity and Voltage Drop

A detailed guide to AWG sizing, ampacity derating, and voltage‑drop calculations for reliable industrial wiring.

August 11, 2026

Service Factors and Safety Factors in Component Selection

Clarifies the catalogue service factor, how it differs from a safety factor, and where it belongs in the design chain for drives, gearboxes, chains.

August 11, 2026

Keys and Keyways: Types, Sizing and Alternatives

A practical guide to selecting key types, sizing them from standard tables, and evaluating alternatives for reliable shaft‑hub torque transmission.

August 11, 2026

Hazardous Area Classification: Divisions, Zones and Protection

A technical guide to North American Class/Division and IEC/ATEX Zone systems, protection methods, temperature classes, and equipment selection for explosive.

August 11, 2026