Appelbaum: Much of the world started moving to the metric system in the late nineteenth century. You've written that the United States didn't follow, because of “the humble screw thread.” ...

For those times when you could really use a quick 3D model, this metric screw generator will do the ... including fine-tuning the thread sizing. We’re fans of OpenSCAD here and appreciate ...

Despite being standardised in the late 1800s, BA threads, the British Association threads used in old electrical equipment, including vehicle magnetos, are based on the metric system ... 0.9 to get ...