1. Armor steel
It starts at the steel mill, not the tank plant. Rolled homogeneous armor (RHA) is poured to a very specific recipe, rolled into plates 20–80mm thick, then heat-treated for hardness without becoming brittle. The plates ship to the tank factory cut roughly to shape.
2. Hull welding
The plates are jigged into a hull skeleton and welded together — almost always by humans, because the welds are deep and the tolerances on armor joints matter for ballistic performance. A modern MBT hull has hundreds of meters of structural weld. Inspection follows every long pass.
3. Composite armor modules
Separate modules — ceramic + tungsten + filler sandwiches — are manufactured off the line and bolted into pockets on the hull and turret. On the Leopard 2 and Abrams, the front and side modules are the most expensive single items on the tank.
4. Turret assembly
The turret is built as its own subassembly in a parallel bay: cast or welded shell, gun trunnion, ammo bustle, hatches, optics housings. It mates to the hull near the end of the line on a single ring bearing that costs more than most cars.
5. Powerpack integration
The engine and transmission come in as a single sealed powerpack — designed for field swap in under an hour, so it drops into the rear hull bay in much the same way at the factory. Fuel lines, cooling, electrical, exhaust all connect at known points.
6. Electronics and fire control
The ballistic computer, stabilizer, optics, displays, comms, BMS, GPS, APU controls — all installed and wired into a single combat data bus. Hundreds of connectors, thousands of meters of harness. Every cable is tested before the next system goes in.
7. Gun installation
The smoothbore (120mm or 125mm) drops into the turret trunnion. It's then bore-sighted against the primary optic so that "where the gunner is looking" and "where the round will land" are the same line.
8. Test and qualification
Every tank drives. Every tank shoots. The factory has its own proving ground for gun accuracy, traverse, stabilizer, mobility, fording and electromagnetic checks. Anything that fails goes back to the bay it came from.
9. Paint and delivery
Last station is the paint booth — usually CARC (chemical agent resistant coating), in the customer's camouflage scheme. Then the tank is loaded on a flatcar or a heavy transporter and shipped to the receiving unit. Total time on the floor: 3–6 months per tank, depending on plant tempo.