Proof tools universal wrench can automatically adjust according to your request within a certain range, saving twist change several different bolt wrench time. Proof universal wrench is a tool for flammable gases places, made of aluminum bronze, beryllium copper alloys. Widely used in petroleum, chemical, and other potential fire and explosion hazards in the environment, but also good mechanical machinery essential for the maintenance tools. Both qualities can play a proof function, and where beryllium alloy products can also play a shielded function. Currently in the domestic production, sales, distribution of explosion-proof tools to distinguish the material can be divided into two categories: 1. aluminum-copper alloy (commonly known as aluminum bronze) proof tools, specific material is a high purity copper matrix by adding an appropriate amount of aluminum, nickel, manganese, iron and other metals, copper-based alloy composition. 2. beryllium copper alloy (commonly known as beryllium bronze) proof tools, specific material is a high purity copper matrix by adding an appropriate amount of beryllium, nickel and other metals, copper-based alloy composition. Both thermal conductivity, electrical conductivity materials are very good specifications:. 5--20,10--30,15--40,30--60mm