But “cheap” is the point, according to Seurat . The company says it’s solved the biggest challenge in 3-D printing, by building machines that produce parts many times faster than rival printers. That means even inexpensive parts can be printed at a cost that’s competitive with old-school methods like milling and stamping. But the way T-nuts are being made at Seurat Technologies in Wilmington is as high-tech as it gets. Seurat is printing them out of powdered steel, using a method with lasers originally developed for building nuclear fusion reactors. It almost seems like overkill to use such an advanced...