Grinding professions know their trade is dangerous and tricky due to the special qualities of their air tools. An important part of any project of this magnitude needs dedicated training for the individual to perform it well and produce the best product possible. Many times sophisticated equipment such as angle die grinders are used which are composed of stones of abrasives that are bonded together into different shapes such as ball, cylinder and cones depending on the specific project. Care must be taken to implement safety precautions. Many accessory items are available.