grinder cutting disc popular for industrial working and home use could be use for metal situation. heavy duty quality and long time use. Grinder Cutting Disc 4" cutting 100*2.0*16 4" cutting 100*3.0*16 4.5" cutting 115*3.0*22 5" cutting 125*3.0*22 6" cutting 150*3.0*22 7" cutting 180*3.0*22 9" cutting 230*3.0*22 WHO WE ARE Yongkang Nova Hardware Co., Ltd. Established in 1988yr. From a small home made workshop. Until 2005yr we have been own 4000squares big factory. Appreciate NOVA hardwork team. Selecting The Appropriate Grain Of Cutting Wheel Grinding Wheel There are three cutting grains commonly used in bonded abrasive cutting wheels: aluminum oxide, zirconia alumina and ceramic alumina. Aluminum oxide wheels provide an aggressive cut out of the box, but immediately begin dulling from the first cut. Ceramic alumina grains self-sharpen and are the most resistant to heat, providing a consistently high cut rate and longer life. Zirconia alumina grains are harder and sharper than aluminum oxide grains and provide an excellent value. Keep in mind that product cost also typically increases along with durability and cut rate.