IFLScience on MSN16 時間
2,000-Year-Old Jewelry Was Made Using Sophisticated Diamond Drills
The nomadic tribes that occupied Central Asia 2,000 years ago used diamond drills to perforate gemstones when manufacturing ...
We Repeatedly Drilled into Three Types of Metal to Find the Best Cobalt Drill Bits
Working with hard metals requires the best cobalt drill bits. We tested top picks to see which bits could bore through the toughest metals. Check out our reviews and discover which one came out on top ...