Guides
In-depth electrical engineering guides on AWG wire sizing, metric cable sizes, conductor classes, SWG, kcmil to mm² conversion, and circular mils.
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9 guides · AWG · metric · conductor fundamentals
Circular Mils Explained: cmil, kcmil and MCM
What circular mils are, why the unit exists (to cancel pi in round-conductor area math), how to convert cmil to mm², and the difference between kcmil and the older MCM label on North American cables.
Why AWG and Metric Wire Sizes Never Line Up
12 AWG converts to 3.31 mm² but you cannot buy a 3.31 mm² cable. Why the two systems are fundamentally different, how to round safely, and which four gauge sizes genuinely pass a metric resistance limit.
Conductor Classes 1, 2, 5 and 6 Explained
IEC 60228 Classes 1 (solid), 2 (stranded), 5 and 6 (flexible) — what the class number actually means, when to use each one, the minimum wire counts, and how stranded resistance limits vary with class.
AWG Diameter vs Cross-Section: Two Different Answers
Why 12 AWG has both a 2.05 mm diameter AND a 3.31 mm² label — which one to use for ferrules/glands vs cable sizing vs purchase orders, and the stranded-wire trap that catches everyone.
American Wire Gauge: How AWG Sizes Are Derived
The geometric series behind AWG — the two fixed points (4/0 = 460 mils, 36 AWG = 5 mils), the 1.1229 step ratio, formula to compute any gauge, and the 3-6-10 shortcuts for on-site estimation.
Copper Wire Strands: Counts, Construction and Trade-offs
Copper wire strands come in counts of 7, 19, 37, 61 and 91 for a reason. What decides the number, what stranding costs in diameter, and how to read a stranded-conductor datasheet.
SWG to mm: Standard Wire Gauge Conversion Table
SWG to mm for every gauge from 7/0 to 40, with the cross-section in mm2. SWG and AWG are different systems, and the same number means a different wire.
kcmil to mm2 Converter: Exact Area and Metric Size
kcmil to mm2 for every standard size from 250 to 2000 kcmil, with the exact cross-section, the IEC 60228 size to specify and the equivalent conductor diameter.
IEC 60228:2023 Explained: Conductor Classes and Limits
IEC 60228:2023 sets the metric conductor sizes, the four classes and the resistance limits every cable is tested against. What is in edition 4 and what changed.