Spanners are the main products which make up the drop forged process category;
The drop forging process involves cropping a bar or rod of chrome vanadium steel into suitable blanks which are heated to between 1100 and 1260 degrees centigrade in diesel furnaces. The red hot blanks are removed from the furnace and then drop forged into a forging die.
After cooling, the excess material is trimmed off and the products are then machined. The exact working profiles, either hexagon, double hexagon or open end profiles are broached according to international dimensions and tolerances.
The next process is hardening and tempering. The products are heated to approximately 850 degrees and quenched in a water solution. Tempering follows at a temperature of between 200 and 300 degrees depending on product and material, and finally the products are allowed to air cool.
Any distortions which have occurred in the hardening process are corrected in the straightening process.
The products are forwarded to the grinding department for vibro-polishing, shoulder, ring and shank grinding. After shot blasting, the products are finally sent for a nickel-based chrome electro-plating finish before being sent to the packing department.