JLCCNC Blog

Design Tips & Best Practices

GD&T Datum: Definition, Types, Symbols, and Datum Reference Frame

Key Takeaways A datum in GD&T is a theoretically exact reference used to locate or orient other features on a part. It is not the physical surface itself. A datum feature is the physical feature identified on the part and used to establish a datum. The datum itself is the theoretically exact geometric reference derived from that feature. Datums become especially important when several features have to work together. A hole pattern, bearing bore, mounting face, or mating surface may need to establish t......

Sep 30, 2026

Manufacturing Solutions

Rapid Prototyping Guide: Processes Compared and How to Choose the Right Method for Manufacturing

What Is Rapid Prototyping (AI generated) Various rapid prototyping parts including 3D printed, CNC machined, and sheet metal components on a workshop table. Rapid prototyping is a manufacturing approach that produces physical parts directly from CAD data within hours or days, enabling engineers to quickly validate design, fit, and function before full-scale production. Modern shops use several methods under this umbrella. 3D printing, CNC machining, and sheet processes all fall into the rapid prototyp......

Sep 30, 2026

Sheet Metal Fabrication

Galvanized Sheet Metal: Grades, Specs & When to Use It

Galvanized Sheet Metal: Grades, Specs & When to Use It A design engineer specs "galvanized sheet metal" on a drawing and sends it out for quotes. Three shops come back with three different prices, and one of them asks a follow-up question the others didn't: which gauge, which coating class, hot-dip or electro-galvanized? That question is the difference between a part that survives outdoors for fifteen years and one that starts showing rust spots after eighteen months — and it's the kind of detail that......

Sep 30, 2026

CNC Machining Fundamentals

What Are Secondary Operations in Manufacturing?

Key Takeaways Secondary operations refine a part after its main production stage. Their classification depends on the production route. Typical tasks include machining, heat treatment, finishing, joining, and marking. Final drawing requirements help determine which added steps are needed. Extra stages can influence cost, lead time, handling, and inspection. Secondary operations are additional manufacturing steps performed after an earlier production stage to bring a part to its required final conditio......

Sep 30, 2026

Surface Finishing Processes

How to Remove Anodizing from Aluminum Parts

Key Takeaways Chemical stripping is commonly used when anodizing needs to be removed from most or all of an aluminum part, but the process can also attack the underlying aluminum if it is not controlled. Mechanical removal works well for accessible areas but can change the surface texture and remove more base metal than intended. CNC machining gives better control when a defined anodized area needs to be removed from a precision part. Laser-based removal can be useful for controlled localized treatmen......

Sep 30, 2026

CNC Programming

What Is CNC Programming? A Complete Guide

What Is CNC Programming? A Complete Guide A finished CAD model doesn't cut anything by itself. Between a 3D design sitting on a screen and an actual part coming off a machine, there's a translation step that turns geometry into motion — where the tool goes, how fast it moves, when it changes, when coolant kicks on. That translation is CNC programming, and it's easy to take for granted until something in it goes wrong: a program that runs a toolpath through a clamp, a feed rate that's fine on paper but......

Sep 29, 2026