JLCCNC Blog

Sheet Metal Fabrication

Hot Rolled vs Cold Rolled Steel: Key Differences, Cost, and Applications

Key Takeaways • Hot rolled vs cold rolled steel comes down to processing history: hot rolled steel is shaped at high temperature, while cold rolled steel is further processed at room temperature for better surface finish and tighter tolerances. • In sheet metal applications, cold rolled steel is usually preferred for enclosures, panels, and precision parts because it offers smoother surfaces and more consistent thickness. • Hot rolled steel is typically better for structural frames, supports, and heav......

Aug 20, 2026

Industry Use Cases

CNC Machining for Electronic Hardware: Design, Tolerances, and Manufacturing Considerations

(AI-generated) CNC milling of an aluminum electronics enclosure CNC machining plays a supporting but critical role in electronics manufacturing. While PCB fabrication creates traces, vias, and plated circuit features, CNC machining is used to produce the structural and mechanical parts that help the final device function reliably. What Is CNC Machining for Electronics CNC machining for electronics is the process of manufacturing high-precision mechanical parts used to support, protect, align, cool, or......

Aug 20, 2026

Design Tips & Best Practices

Least Material Condition (LMC) in GD&T

Key Takeaways LMC is the size condition where a feature contains the least material allowed by its size limits. For a hole, this is the largest permitted diameter. For a shaft or pin, it is the smallest permitted diameter. LMC is mainly useful when remaining material around a feature needs to be protected, such as the wall between a hole and an outside edge. When Ⓛ is added to a geometric tolerance, the feature can gain additional geometric tolerance as its actual size moves away from LMC. LMC is esta......

Aug 20, 2026

Design Tips & Best Practices

Maximum Material Condition (MMC) in GD&T

Key Takeaways MMC is the condition in which a feature of size contains the maximum amount of material within its specified size limits. For a shaft or pin, this is the largest permitted size; for a hole, it is the smallest permitted size. MMC is used with features of size, such as holes, shafts, pins, and slots. When the MMC symbol Ⓜ is added to a geometric tolerance, the feature can gain bonus tolerance as its actual size moves away from MMC. MMC is commonly applied to holes, pins, and other mating f......

Aug 20, 2026

Design Tips & Best Practices

Engineering Fits: Clearance, Transition, and Interference Fits

Key Takeaways Engineering fits describe the dimensional relationship between two mating parts, specifically whether assembly produces clearance (gap), interference (overlap), or a result that could be either. Clearance fit always produces a gap; the shaft is always smaller than the hole. Interference fit always produces overlap; the shaft is always larger than the hole and force or temperature is needed to assemble. Transition fit can produce either a small clearance or small interference depending on......

Aug 19, 2026

CNC Machining Fundamentals

Tapped Hole vs Threaded Hole: Differences, Machining Methods & Design Guide

Key Takeaways A tapped hole is a threaded hole produced with a tap; “threaded hole” is the broader term covering internal threads made by tapping, thread milling, or thread forming. Internal threads are produced by tapping, thread milling, or thread forming, chosen based on material, thread size, hole geometry, and production requirements. A threaded-hole callout should specify thread size, pitch, standard, tolerance class, and usable depth. Thread size, depth, wall thickness, and tool accessibility s......

Aug 14, 2026