A model kit consisting of magnetic rods and steel balls,whichis generally sold as a desktop toy, has been utilized to constructphysical models for teaching packing arrangements of metallic crystal.All four basic metallic crystal structure models are easily constructedlayer by layer, and corresponding unit cells can be naturally derivedfrom the packing structures. The low-cost models based on magneticrods and steel balls are portable and easy-to-construct, and teachingpractice shows that they can guide students to gain a deeper understandingof packing arrangements of metallic crystal. Positive feedback fromstudents indicates that they are interested in constructing modelswith the rods and balls by themselves. Overall, compared with theexisting crystal structure models, these models combine the characteristicsof portability, low cost, and ease of construction; therefore, theyhave great potential to enhance students' learning of metalliccrystal structures through hands-on activities or classroom demonstrations.