New orders for US durable goods fell a surprise 3.6% in April from March.
Sales of cars and parts, and of computers, each down 4.4%, were among the hardest hit, with the disruption to supply chains from Japan's earthquake and tsunami the likely cause.
However, other sectors such as metal goods and machinery also did badly, according to the Commerce Department.
The weak April figure partly reflects a jump in orders the month before, with March's increase revised up to 4.4%.
Economists had expected a fall of only 2.2%. However, the increase in March's figure from an earlier 4.1% estimate also came as a surprise.
"It's another modestly disappointing data point in a long series of slightly disappointing data points that we've gotten in the last month," said Fred Dickson, chief market strategist at brokerage DA Davidson.
"[It is] not indicative of an economic downturn, just kind of paints a picture that the economy is in a momentary lull."
New orders for civilian aircraft - a typically volatile item - fell 30% in the month, after Boeing, which dominates the sector in the US, experienced a quiet patch in its orderbook.