Giano J, Abu R, Mukhnizar M. Analysis of the Tempering Process Results with Temperature Variations on the Mechanical Properties of AISI 4340 Material Hardness. TOFEDU [Internet]. 2025 Dec. 5 [cited 2025 Dec. 8];4(8):4814-20. Available from: http://journal.tofedu.or.id/index.php/journal/article/view/1182