We achieved decremental margins of 25% for the year through value-based pricing and difficult but necessary cost actions of $45 million.
Aerospace and defense improved their margins by 290 basis points despite lower volume.
Notably, aerospace and defense won 20 new programs, including 60 defense and four in commercial.
We continue to invest in innovation, launching 49 new products in 2020 versus 33 in 2019.
We delivered on our free cash flow commitments throughout the year and ended with strong free cash flow of $20 million in the fourth quarter.
And finally, we reduced our debt by $126 million or 22%.
We booked orders of $168 million in the quarter, which was flat sequentially and down 25% organically.
Sequentially, industrial was up 12% in the quarter.
A&D had lower orders sequentially, down 21% and due to the timing of large naval program orders that pushed into 2021.
Revenue in the quarter was $208 million, up 10% sequentially, driven by strong defense deliveries, mainly on U.S. Naval programs and moderate growth across most end markets in industrial.
Adjusted operating income was $23 million, representing a margin of 11.2%, up 200 basis points from the prior quarter.
As a result of improved operating income, the company delivered $0.66 of adjusted earnings per share.
Finally, we generated strong free cash flow of $20 million during the fourth quarter, as we exited the year with operational cash flow unencumbered by transformation disbursements.
In Q4, industrial segment orders were up 12% sequentially, down 22% organically.
Revenue in the quarter was $131 million, up 4% from prior quarter and down 13% organically.
We exited the year with an operating margin of 9%, a sequential improvement of 160 basis points, driven by price increases and cost actions taken throughout the year.
Our aerospace and defense segment booked orders of $47 million in the quarter, down 21% sequentially and down 33% versus prior year.
Revenue in the quarter was $78 million, up 25% from prior quarter.
Strong defense deliveries mostly offset the COVID-19 impact, on commercial Aerospace, resulting in only 3% lower revenues versus by year.
Finally, operating margin was 24% in the quarter, roughly flat sequentially and year over year.
Pricing, up 3%, combined with factory and cost actions drove strong margins in line with prior year despite lower revenue.
For Q4, the effective tax rate was approximately 14%.
The company took a non-cash charge of approximately $15 million to record a valuation allowance against its remaining deferred tax assets in Germany.
Looking at special items and restructuring charges, we recorded a total pre-tax charge of $13.4 million in the quarter.
The acquisition-related amortization and depreciation was a charge of $12 million with the remaining charges associated with restructuring activities in the quarter.
Interest expense for the quarter was $8.5 million, down $2.3 million compared to last year as a result of lower debt balances.
Other income was approximately $1 million, primarily driven by pension income.
Finally, corporate costs were $7.8 million in the quarter.
As Scott mentioned previously, our free cash flow was $20 million in the fourth quarter, up 11% compared to 2019.
We used the proceeds from the sale of our instrumentation and sampling business to reduce our net debt to $443 million, a reduction of $126 million or 22% year over year.
We're expecting Q1 industrial revenue to come in between down 1% and up 4% year over year.
Pricing is expected to be a benefit of roughly 1%, consistent with prior quarters.
Revenue in the first quarter is expected to be down 7% to 12% versus prior year.
defense revenue is expected to be down 1% to 5% due to the timing of large defense shipments and lower U.S. defense spares orders leading into the quarter.
We anticipate growth of 5% to 10% from our other OEM group, which includes products for drones, missiles and helicopters.
Commercial revenue is expected to be down between 35% and 40%, in line with the broader commercial aerospace market.
Pricing is expected to be a benefit of 1% in the quarter, but in line with 2020 for the full year.
In addition to the revenue guidance that Scott provided, we're expecting incremental margins of 30% to 35% in industrial and decremental margins of 30% to 35% in aerospace and defense.
We're also planning for corporate cost of $8.5 million, higher than our expected full-year run rate, due to the timing of certain expenses, such as RFPs.
Interest expense is expected to be roughly $8.5 million in Q1.
We are expecting organic revenue growth of 0% to 4%, and with aerospace and defense expected to grow at low to mid-single digits and industrial at low single digits.
We're expecting adjusted earnings per share of $2 to $2.20, a 40% to 54% increase versus 2020.
Finally, we're planning to deliver free cash flow as a percent of adjusted net income of 85% to 95%.

Summary:
Revenue in the quarter was $208 million, up 10% sequentially, driven by strong defense deliveries, mainly on U.S. Naval programs and moderate growth across most end markets in industrial.
As a result of improved operating income, the company delivered $0.66 of adjusted earnings per share.
We are expecting organic revenue growth of 0% to 4%, and with aerospace and defense expected to grow at low to mid-single digits and industrial at low single digits.
We're expecting adjusted earnings per share of $2 to $2.20, a 40% to 54% increase versus 2020.