Why are factory backlogs growing despite weak shipment growth?

Backlogs are expanding because input cost inflation, tariff uncertainty, and supply constraints (steel shortages, worker scarcity) are slowing production and delivery. Manufacturers report orders through year-end above forecast, but production cannot keep pace. The unfilled-to-shipment ratio at 6.87 reflects a structural lag in production capacity relative to demand.

How much have freight and fuel costs increased recently?

Diesel fuel, which benchmarks most freight surcharges, hit a record $6.529 per gallon on September 21, 2026. Freight has been on ISM's rising-price commodity list for seven consecutive months. No commodities were reported down in price in September, reflecting broad-based cost inflation.

What impact are Canada tariffs having on cross-border supply chains?

Canada's retaliatory tariffs of 15-50% on C$27.6 billion in U.S. goods (effective September 8) are causing immediate supply chain disruption. Manufacturers report doubled lead times for semiconductors, electronics, and government-critical work. Cross-border supply chains developed over years are being destabilized, and customers are deferring capital expenditures due to cost and demand uncertainty.

What are the biggest operational constraints manufacturers face right now?

Supply chain professionals cite three critical constraints: severe worker shortages limiting production output, steel availability deterioration with expected production delays, and freight cost inflation. The ISM Prices Index at 77.9 reflects steel, aluminum, and petroleum-based product increases compounded by tariffs, creating cascading cost pressures through the value chain.

Are inventories being replenished or depleted?

Manufacturer inventories contracted in September with the ISM index at 48.6 (down 2 points). Customer inventories remain at critically low levels (index at 41.6), a 24th consecutive month in 'too low' territory. This typically signals positive future production demand, but backlogs and cost uncertainty may be suppressing actual orders.

Manufacturing

High Impact

Factory Backlogs Hit 26-Month High as Freight and Steel Costs Soar

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The signal

U.S. factory backlogs reached $1.61 trillion in August, rising for 25 of the last 26 months, while shipments stalled and new orders barely moved. Transportation equipment drives the backlog surge, with the unfilled-to-shipment ratio climbing to 6.87.

The Institute for Supply Management's September prices index spiked 6.8 points to 77.9, the largest monthly increase recorded, driven by steel and aluminum inflation, petroleum-based product costs, and tariff impacts. Diesel fuel hit a record $6.529 per gallon on September 21, and 58.6% of manufacturers reported paying higher prices, up from 46.2% in August.

Canadian retaliatory tariffs (15-50% on C$27.6 billion in U.S. goods) are compounding supply chain instability, forcing manufacturers to defer purchases and extend lead times indefinitely. Worker shortages and steel availability constraints are now critical operational bottlenecks alongside elevated freight and component costs.

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Frequently Asked Questions

What This Means for Your Supply Chain

Simulation Suggestion

immediate

What if tariff rates on U.S.-Canada trade remain at current levels through year-end?

Model the impact of sustained 15-50% tariff rates on semiconductor, electronics, and machinery imports from Canada through December 2026. Assume lead times remain doubled for critical components and assess how capital expenditure deferrals by end customers ripple through supplier demand forecasts. Calculate cost pass-through to downstream customers and inventory repositioning requirements.

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Simulation Suggestion

this month

What if steel availability worsens and lead times extend by 4-6 weeks?

Project the operational impact if steel supply tightens further and procurement lead times stretch from current levels to 4-6 weeks beyond forecast. Model how this cascades through fabricated metal products, transportation equipment, and machinery manufacturing. Assess how production delays compress delivery windows and whether safety stock policies must increase despite cost pressures.

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Simulation Suggestion

this month

What if diesel prices climb another $0.50-$1.00 per gallon by Q4?

Simulate the cost impact if diesel averages $7.00-$7.50 per gallon through Q4 2026. Calculate freight surcharge escalations for both inbound procurement and outbound shipments. Model customer pushback on price increases and evaluate whether mode shifts (rail vs. trucking) become economically justified. Assess margin compression for 3PL providers and carriers.

Run this scenario

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