Knowledge Base

Machining Articles & Guides

Practical reference material for machinists — formulas, reference tables, and worked examples covering the most common shop calculations.

Speeds & Feeds: Calculating RPM, Cutting Speed & Feed Rate

The core formulas for spindle speed, surface footage, and feed rate for turning and milling — with worked examples for common materials and practical tips for reading your chips.

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Thread Classes Explained: 1A/2A/3A, 1B/2B/3B, and Metric 6g/6H

What tolerance class actually controls, how allowance works, the difference between Class 2 and Class 3, and how metric ISO classes map to their UN equivalents.

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Tap Drill Sizing: Choosing the Right Drill for Any Thread

How thread engagement percentage works, when to deviate from 75%, the difference between cutting and forming tap drill sizes, and reference tables for UNC, UNF, Metric, and NPT.

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GD&T True Position: How It Works and How to Calculate It

What true position controls, the TP = 2√(ΔX² + ΔY²) formula, and how MMC and LMC bonus tolerance works — with pass/fail worked examples.

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