Overview Product Description Heavy-duty drill bits. Black oxide-coated to improve drilling efficiency and reduce heat and build-up. For drilling through metal, wood, fiberglass, stainless steel. The product is manufactured in china Product Videos Custom Field Product Reviews Write a Review Write a Review × Mibro 271891DB Silver and Demming Drill Bit Rating * Select Rating 1 star (worst) 2 stars 3 stars (average) 4 stars 5 stars (best) Name Email * Review Subject * Comments *