Nobody crafts this. It cannot be crafted or researched, so the Level 3 recipe stays locked, and every one in a box came off the heavy scientists at an Oil Rig, as its item page says. What the bill tells you is the trophy's worth in parts: twice the pipes of a rocket launcher and more than a crafted flamethrower.
So the real question is fire or recycle. Kept by the door, it is a nasty answer to raiders squeezing through a doorway, and it runs on the same low grade fuel as the crafted one. Out roaming it is dead weight. If your group defends from the roof with rifles, it earns nothing sitting in a box.
The recycler pays well by loot standards. The ordinary one returns half the pipes, half the propane tanks and half the fuel, and those pipes cover two rockets.
Questions
Military Flame Thrower ×10: how many resources?
High Quality Metal ×350, Cloth ×250, Animal Fat ×750, Empty Propane Tank ×40, Metal Pipe ×80.
Which workbench does Military Flame Thrower need?
Workbench level 3.
How long does Military Flame Thrower take to craft?
2 min 40 s for one, every step included.
How much scrap does researching Military Flame Thrower take?