Good tap and die sets come with cases that are designed to protect them from impact, dust, or corrosion. Certain types of industrial environments will benefit from the more robust tight-fitting cases while some may not need anything beyond a blow-molded case with foam lining on the inside. Other important things to look for in an industrial situation are sets that are nitride heat treated or even hand polished which can eliminate problems caused by grinding debris. No matter what kind of tool you are looking for, it is always best to ask the manufacturer about any warranty coverage they offer during your purchase. If more expensive tools have an extended warranty policy then it is worth considering investing in one versus getting a cheaper set which only comes with brief coverage.