Senior Vice President and Chief Financial Officer at IDEX
Thanks, Eric. I'll start with our consolidated financial results on slide 9. Fourth quarter orders of $795 million were up 17% overall and up 13% organically. Organic orders increased across each of our segments. For the year, orders were up 26% overall and up 21% organically. We experienced a strong rebound in demand for our products across all our segments and steadily built our backlog in each quarter of 2021, totaling $266 million for the year. Relative to full-year 2019, organic orders were up 15%. Q4 sales of $715 million were up 16% overall and up 11% organically.
We experienced a strong demand rebound from 2020, but our results were tempered by supply chain and COVID production limitations. Full-year sales of $2.8 billion were up 18% overall and up 12% organically. We saw favorable results across all our segments and, again, strong performance relative to full-year 2019 with organic sales up 4%. Fourth quarter gross margins expanded 20 basis points to 44%. For the full year, gross margins expanded 60 basis points and adjusted gross margins expanded 80 basis points to 44.7%, primarily driven by strong volume leverage.
Q4 operating margin was 22.7%, up 10 basis points compared to prior year. Adjusted operating margin declined 60 basis points, driven by a rebound in discretionary spending, targeted resource investments, and a dilutive impact of acquisition-related intangible amortization, partially offset by volume leverage. Full-year operating margin was 23%, up 90 basis points compared to the prior year. Adjusted operating margin was 23.9%, up 110 basis points compared to prior year. I'll discuss the drivers of adjusted operating income on the next slide.
Our fourth quarter effective tax rate was 22.5%, relatively flat compared to the prior year ETR of 22.2%. Our full year effective tax rate was 22.5%, compared to 19.7% in the prior year due to lower tax benefits associated with executive compensation and the non-repeat of benefits associated with the finalization of the global intangible low income tax regulations in 2020. Q4 net income was $119 million, which resulted in EPS of $1.55. Adjusted net income was also $119 million, with adjusted EPS of $1.55, which was up $0.18, or 13% over prior year adjusted EPS.
Full year net income was $449 million, which resulted in EPS of $5.88. Adjusted net income was $482 million, resulting in an adjusted EPS of $6.30, up $1.11 or 21% over prior year adjusted EPS. The tax rate movement I mentioned drives a $0.23 differential in EPS as compared to the prior year. Said differently, our EPS would have expanded by $1.34 or 26%, had 2021 been taxed at the 2020 rate. Finally, free cash flow for the quarter was $136 million, 115% of adjusted net income. For the year, free cash flow is $493 million, down 5% versus last year and was 102% of adjusted net income.
This result was impacted by a volume driven working capital build and higher capex, partially offset by our higher earnings. We spent over $70 million on capital projects this year, an increase of over $20 million versus 2020. Moving on to slide 10, which details the drivers of our adjusted operating income, adjusted operating income increased $125 million for the year compared to 2020. Our 12% organic growth contributed approximately $106 million flowing through at our prior-year gross margin rate. We levered well in this volume increase and our teams drove operational productivity to help mitigate the profit headwinds we experienced from increased supply chain costs and the associated inefficiencies.
Although we have maintained positive price cost for the year, inflation continues to ramp and we saw a compressed price/cost spread versus historic levels, which pressured our op margin rate and flow-through percentages. The positive mix is primarily a result of the portfolio and business mix normalizing to pre-pandemic levels that had a negative impact on our results last year. We reinvested $35 million back into the businesses, taking the form of a partial rebound in discretionary spending to pre-pandemic levels, higher variable compensation expenses and targeted reinvestment in resources to drive growth.
Despite this incremental spend and a challenging supply chain environment, we achieved a solid 38% organic flow-through for the year. Flow-through was then negatively impacted by the dilutive impact of acquisitions and FX getting us to a reported flow-through of 30%. With that, I'd like to provide an update on our outlook for the first quarter and full year 2022. I'm on slide 11. As a reminder, going forward, we will be adjusting EPS for acquisition-related intangible amortization in both our guidance and results. Our fourth quarter adjusted EPS under this definition would have been $1.71 per share, while our full year 2021 adjusted EPS would have been $6.87 per share. Under this new definition, for the first quarter of 2022, we are projecting GAAP EPS of $1.57 to $1.60 and adjusted EPS to range from $1.73 to $1.76.
We expect organic revenue growth of 6% to 7% for the first quarter and operating margin of approximately 23%. Q1 expected results incorporate headwinds arising from COVID-driven absenteeism and supply chain production constraints. The first quarter effective tax rate is expected to be approximately 22.5%. We expect FX to be unfavorable to our top line by 1% and acquisitions to provide a 4% benefit. Corporate costs in the first quarter are expected to be around $19 million. Turning to the full year 2022; we project GAAP EPS of $6.70 to $7, and adjusted EPS to range from $7.33 to $7.63.
We expect full-year organic revenue growth of 5% to 8% and operating margins to be around 24%. We expect FX to be unfavorable to our top line by 1% and acquisitions to provide a 2% benefit. The full-year effective tax rate is expected to be around 22.5%. Capital expenditures are anticipated to be around $90 million, an increase over 2021, as we continue to identify opportunities to reinvest in our core businesses. Free cash flow is expected to be approximately 105% of adjusted net income and corporate costs are expected to be approximately $80 million for the year.
Our earnings guidance excludes impacts from future acquisitions and any future restructuring charges. Nexsight is excluded from the figures above, as the transaction is yet to close. Next, I will provide some additional details regarding our 2022 guidance for the full year. I'm on slide 12. On an operational basis, we expect supply chain constraints to mitigate our output for the first half of the year, muting an otherwise strong demand environment. Therefore, we are projecting organic revenue for the year to be up 5% to 8%, which translates to an EPS impact of $0.60 to $0.95, depending on the top line results.
This range also assumes improving price cost. We continue to drive operational productivity across the portfolio and expect to see benefits from our 2021 restructuring actions. This will drive $0.20 to $0.25 of favorability next year. We also continue to invest in the resources required to grow in the current year and beyond. These investments will reduce EPS by $0.20 to $0.25 and are funded by the productivity gains I mentioned previously. Our discretionary spend partially recovered to pre-pandemic levels in 2021, and we expect this spending to be fully recovered by the end of 2022.
The unfavorability impacts EPS by $0.20 to $0.25. I'll note that we were ramping spend to pre-pandemic levels, but with 20% higher revenues. ABEL has one partial quarter and Airtech has two quarters inorganic results included in our guidance. We expect the acquisitions to contribute $54 million of revenue and $0.08 of EPS. The incremental amortization that we see in 2022 versus 2021 is largely related to these acquisitions and will provide an additional $0.05 of EPS. Now, let's take a look at a couple non-operational items.
First, our guide assumes no impact from tax, as our guided rate is flat year-over-year. Second, we expect a 1% headwind from FX providing $0.07 of EPS pressure. So in summary, we are projecting organic revenue growth of 5% to 8% for the year, adjusted EPS expectations on the range of $7.33 to $7.63, a 7% to 11% growth over 2021. Implied in our guidance is mid- to high-20s year-over-year flow-through on the low end and 30% on the high end.
With that, I'll throw it back to Eric for some final thoughts.