Workshop extension cords don't expire on a calendar.

Replace them when they show damage, not after a set time.

Daily workshop use is rough on cords—abrasion, chemicals, sharp metal edges, heavy tools pulling on them. But a cord that looks good and passes a continuity test is still safe, regardless of age. The real danger is ignoring visible wear.

Inspect yours every few months. Look for cuts in the jacket, exposed conductors, cracked insulation near the plug or connector, or any place the cord feels stiff or soft. If you see copper, bin it. If the ground prong is bent or loose, bin it. If it gets wet or crushed, bin it. For heavy daily use, you might get 2–4 years before something shows up, but I’ve seen cords last a decade in clean shops.

Don’t push it. A new cord is cheap. A workshop fire is not.