Fabricated wrought-iron cannons made in 1844 demonstrated the superiority of welding with a hydraulic press instead of forge hammers. Daniel Treadwell in an early example of additive manufacturing welded multiple discs together to make cannon that then required only finishing on a lathe and attaching trunnions. His cannon sustained proof testing what would have quickly destroyed equivalent cast-iron guns. When that same year a large wrought-iron cannon built up from staves and rings by hammer welding exploded during a public demonstration the subsequent investigation by ordnance officers and a committee of the Franklin Institute chose to overlook incomplete welds and blame the failure on deficient iron used to make the gun. Their conclusion shifted blame from those involved to a distant ironmaker. Development of fabricated cannon and continuous pressure welding then passed to England.

1844 年制造的锻铁大炮展示了用液压机代替锻锤焊接的优越性。Daniel Treadwell 在增材制造的早期示例中将多个圆盘焊接在一起制成大炮，然后只需要在车床上进行精加工并安装耳轴。他的大炮经受住了考验，可以快速摧毁等效的铸铁枪。同年，当一门大型锻铁大炮在一次公开示威中爆炸时，军械官员和富兰克林研究所的一个委员会选择忽视不完整的焊缝，并将失败归咎于使用的铁不足做枪。他们的结论将责任从相关人员转移到遥远的炼铁厂。