BronAL Aluminum Bronze Ring Spanner Set – 13 Nos – 6×7,8×9,10×11,12×13,14×15,16×17,18×19,20×22,21×23,24×26,24×27,25×28,30×32 are Corrosion resistant and is mandantory for working in environments contaning flammable solid, liquids and gases.” &” Aluminum Bronze Hand Tools are Certified for Safety as per IS 4595:1969 2006 Standards and are Torque Tested to IS 6131:1980 Standards. Do not use cheater bars or use external leverage – Misuse not covered under warranty”