Hengshui Jrain Frp fiberglass drum

The hardness of limestone can vary greatly, from relatively soft to extremely hard, depending on factors such as its mineral content and degree of compaction. Soft limestones can be easily drilled using standard drilling equipment, but harder varieties often necessitate more robust machinery and specialized bits. Carbide-tipped drill bits, for instance, are commonly employed due to their durability and ability to withstand the abrasive nature of limestone.

...

One of the key advantages of thread carbide extension rods is their exceptional hardness. Made from a combination of tungsten carbide and cobalt, these rods possess a Rockwell hardness rating of up to 93 HRC, which is significantly higher than conventional steel or aluminum counterparts. This superior hardness allows them to maintain their sharpness and cutting ability even after extended use, reducing the frequency of sharpening and maintenance downtime.

...