AMETEK posted a strong first quarter with sales up 11% to $1.93 billion on 5% organic growth plus acquisitions, while record orders of $2.2 billion (up 23%) lifted backlog to a record $3.87 billion and core operating margins expanded 160 basis points to 27.9%. Diluted EPS of $1.97 beat the guidance range and the company raised full-year earnings guidance, also signing a definitive agreement to acquire defense aftermarket provider First Aviation Services. Management flagged tougher second-half comparisons in medical and several EMG markets and is monitoring modest risk in the small international commercial aviation aftermarket.
Thank you, Stacy. Good morning, and welcome to AMETEK's first quarter 2026 earnings conference call. Joining me today are David Zapico, Chairman and Chief Executive Officer, and Dalip Puri, Executive Vice President and Chief Financial Officer. During the course of today's call, we will be making forward-looking statements which are subject to change based on various risk factors and uncertainties that may cause actual results to differ significantly from expectations. A detailed discussion of the risks and uncertainties that may affect our future results is contained in AMETEK's filings with the SEC. AMETEK disclaims any intention or obligation to update or revise any forward-looking statements. Any references made on this call to historical results will be on an adjusted basis, excluding after-tax, acquisition-related intangible amortization, and excluding acquisition-related cost.
Reconciliations between GAAP and adjusted measures can be found in our press release and on the investor section of our website. We'll begin today's call with prepared remarks, then we'll open up the call for questions. I'll turn the meeting over to Dave.
Thank you, Kevin. Good morning, everyone. AMETEK delivered an excellent first quarter, highlighted by double-digit sales growth, exceptional orders growth, robust core margin expansion, record EBITDA, and a high quality of earnings that exceeded our expectations. We also raised our full-year earnings guidance to reflect our first quarter results and the outlook for the balance of the year. Today, we also announced we signed a definitive agreement to acquire First Aviation Services, an attractive acquisition which strategically broadens our defense aftermarket capabilities. I will provide more details on First Aviation shortly. Let me turn to our first quarter financial results. First quarter sales were $1.93 billion, up 11% from the same period in 2025. Organic sales were up 5%. Acquisitions added 5 points, with foreign currency a tailwind.
Orders were outstanding in the quarter, with broad-based and meaningful growth across all AMETEK divisions. Overall orders were a record $2.2 billion, up 23% versus the prior year, and organic orders were up 22%, leading to a record backlog of $3.87 billion. Operating income in the quarter was $517 million, a 14% increase over the first quarter of 2025. Operating margins were 26.8% in the quarter, and core margins were an impressive 27.9%, up a robust 160 basis points versus the prior year. EBITDA in the quarter was a record $620 million, up 11% versus the prior year, with EBITDA margins a strong 32.1%.
Our excellent operating performance led to strong cash generation, with free cash flow to net income conversion of 107%. Diluted earnings per share were $1.97, up 13% versus the first quarter of 2025, and above our guidance range of $1.85-$1.90 per share. Let me provide some additional details at the operating group level. First, the Electronic Instruments Group. EIG had an excellent first quarter, with double-digit sales growth, strong operating performance, and a meaningful inflection in orders. EIG sales in the quarter were $1.26 billion, up 11% from last year's first quarter. Organic sales were up 2% and acquisitions added 7 points, with foreign currency the balance of the growth. Organic orders for EIG were up an impressive 25% in the quarter.
This growth was broad-based across all EIG divisions and end markets, with notable growth within our defense, power, and semiconductor businesses. EIG's first quarter operating income was $376 million, up 6% versus the prior year. Core operating margins were an outstanding 31.4%, up 40 basis points from the prior year. The Electromechanical Group also delivered excellent results in the quarter, with continued strong sales and orders growth, along with exceptional operating performance, leading to sizable core margin expansion. EMG's first quarter sales were a record $664 million, up 13% versus the prior year. Organic sales were again up double digits at 11%, with foreign currency a 2-point tailwind. Sales growth was broad-based, with our automation, engineered solutions, and aerospace and defense businesses all delivering excellent growth in the quarter.
Additionally, EMG organic orders were again outstanding, up 16% versus the prior year. EMG's operating income in the first quarter was $171 million, up 33% compared to the prior year period. While EMG's first quarter core operating margins were up sharply to 26%, a considerable 410 basis point increase versus the first quarter of 2025. I wanted to take a moment to expand on the strength and breadth of AMETEK's order growth in the quarter. The 22% organic orders growth reflects the ongoing strength within our aerospace and defense markets, as well as the continued strong growth across our automation and engineered solution markets. Importantly, it also reflects a meaningful inflection in orders for our process instrumentation and power businesses in the quarter, as the strong pipeline of opportunities we have been highlighting is translating into substantial orders growth.
Contributing to the order strength were several large orders in the quarter which help fill in our full-year sales outlook. These large orders are aligned with attractive market segments, including defense, space, power, and semiconductor, all markets where AMETEK is poised to benefit from strong and growing demand. Within defense, we are seeing broad-based strength, including within missile defense, UAVs, and naval applications. The growth in defense budgets is being driven by modernization of defense capabilities and the ongoing geopolitical conflicts, creating a strong global growth outlook for defense spending, including from NATO allies. Our aerospace and defense businesses was recently selected to provide a range of technologies in support of three UAV programs, one program in the U.S. and two with NATO allies. Products being provided on these programs include ruggedized thermal management systems, power distribution equipment, advanced sensors, and embedded computing app solutions.
Our EMIP business also provides highly engineered, specialized fluid transfer solutions for critical military and defense applications. In the first quarter, saw strong order growth across many key defense platforms, including in support of nuclear submarines. Within nuclear, we're also seeing strong commercial nuclear demand in orders. AMETEK businesses provide a range of highly specialized products to this market, including fluid transfer solutions, radiation detection equipment, and uninterruptible power solutions in support of nuclear power facilities. Switching to space and satellite communications market, our Kern Microtechnik business recently received a sizable order to provide ultra-precision machining solutions and manufacturing services in support of critical RF components used in low Earth orbit satellites. Kern's advanced precision machining solutions are targeted for mission-critical applications which require maximum accuracy, stability, and repeatability.
Lastly, our Abaco business, a leading provider of ruggedized embedded computing solutions, continues to see strong demand with a significant win in the semiconductor capital equipment market. Abaco recently secured an agreement to provide advanced computing technology to support AI-driven demand for advanced semiconductor tools. Abaco's orders were excellent in the quarter, with strong defense orders in addition to strength in the semiconductor market. The breadth and strength of our orders in the first quarter reflect the continued trust of our customers and our continued delivery of key technology-driven products that meet our customers' most critical needs. Before we move too far off the topic of key programs and our ability to deliver in the most critical and demanding of applications, I want to take a moment to highlight a particularly timely example of our differentiated technology.
AMETEK Sensors and Fluid Management Systems, a leader in advanced specialized sensing solutions for the aerospace, defense, and space markets, provided critical solutions used on the recent Artemis II mission that eclipsed the record for the furthest manned space mission. Our SFMS business provided thin-film pressure transducers that supported mission-critical life support infrastructure on the Orion Multi-Purpose Crew Vehicle. This application demonstrates our ability to serve even the most demanding of applications and our ongoing commitment to reliability, precision, and accuracy. Congratulations to the AMETEK Sensors and Fluid Management Systems team on this exciting success, and also to the four other AMETEK businesses, FMH, UEI, NSI, and Zygo, Pixelink, that also supported the Artemis platform with specialized technology. Now, turning to acquisitions and capital deployment.
With our robust balance sheet, strong cash flows, and disciplined approach to capital deployment, AMETEK is well-positioned to continue driving long-term value through our disciplined acquisition strategy. We are managing a very strong pipeline of acquisition opportunities across a wide range of deal sizes and markets and are encouraged by the strong pipeline of high-quality acquisition candidates. As Dal will touch on, our significant financial capacity provides the opportunity to deploy well over $5 billion in capital while maintaining an investment-grade credit rating. Our top priority for capital deployment remains acquisitions, and we expect to remain active in this area. We were pleased to announce this morning that we've signed a definitive agreement to acquire First Aviation Services, a leading provider of defense and aviation MRO services, as well as proprietary part design and manufacturing.
The combination of First Aviation with AMETEK's MRO business will provide attractive market expansion opportunities and additional scale for our A&D aftermarket businesses. First Aviation is privately held and has six U.S.-based centers of excellence. They have approximately $80 million in annual sales. The acquisition is subject to customer closing conditions, including regulatory approvals. Alongside this acquisition and capital deployment strategy, we continue to invest in our businesses to ensure AMETEK is strategically positioned for long-term sustainable growth. For 2026, we continue to expect to invest an incremental $100 million to support our growth initiatives, with the majority of this investment going into RD&E and sales and marketing initiatives. These investments continue to deliver excellent returns. In the first quarter, our vitality index, which measures sales of new products introduced over the last three years, was an outstanding 25%.
We'll take a moment to highlight an example of an exciting new product from our RTDS Technologies business. RTDS is a leader in real-time digital simulation of power systems, infrastructure, and hardware testing in the loop. Their real-time electromagnetic transient simulators enable detailed studies of power systems, allowing engineers to anticipate system and device behaviors that threaten the stability, resilience, and performance of the power grid. RTDS recently updated their simulator platform with new features, including a data center module and an updated workflow that provides more accurate representations of third-party power solutions. This innovation helps data center operators model the power electronics required for key components, such as the uninterruptible power supply systems and the variable frequency drive used in power and cooling systems.
Thank you, Dave, and good morning, everyone. As Dave noted, AMETEK delivered an outstanding start to the year, highlighted by excellent orders, sales, and earnings growth, robust core margin expansion, and strong cash flow generation. Let me provide some additional financial highlights for the first quarter. First quarter corporate general and administrative expenses were $30 million, or 1.5% of sales. For the full year, we continue to expect corporate general and administrative expenses to be approximately 1.5% of sales. First quarter other operating expenses were $1 million, largely in line with the first quarter of 2025. First quarter interest expense was $21 million, up $2 million from the first quarter of 2025. The effective tax rate in the quarter was 19%.
For 2026, we continue to anticipate our effective tax rate to be between 18.5% and 19.5%. As we have stated in the past, actual quarterly tax rates can differ dramatically, either positively or negatively, from this full year estimated rate. Capital expenditures in the first quarter were $25 million. For the full year, we expect capital expenditures to be approximately $160 million, or about 2% of sales. Depreciation and amortization expense in the quarter was $105 million. For the full year, we expect depreciation and amortization to be approximately $430 million, including after-tax acquisition-related intangible amortization of approximately $210 million, or $0.91 per diluted share.
For the quarter, operating working capital was 17.5%, a 60 basis point improvement versus 18.1% in last year's first quarter. Operating cash flow was $452 million, up 8% versus the first quarter of 2025. Free cash flow was also up 8% year-over-year to $426 million. Free cash flow conversion was strong at 107% for the quarter. For 2026, we continue to expect free cash flow conversion to be approximately 110%-115% of net income. Total debt at March 31st was $2.2 billion, down from $2.3 billion at the end of 2025. Offsetting this debt is cash and cash equivalents of $481 million.
At the end of the first quarter, our gross debt to EBITDA ratio was 0.9x, and our net debt to EBITDA ratio was 0.7x. We continue to have excellent financial capacity, with flexibility to deploy well over $5 billion on growth initiatives and our active acquisition pipeline while retaining an investment-grade credit rating. While acquisitions remain our number one capital allocation priority for use of our free cash flow, we also seek to provide our shareholders with opportunistic share buybacks and a consistently increasing dividend. In February, we announced a 10% increase in our quarterly cash dividend to $0.34 per share, our seventh consecutive year of 10%+ annual increases in our dividend payout.
I would also like to note that we have enhanced our financial reporting this quarter by including AMETEK's gross margin reporting and a related reconciliation on our Investor Relations website. With adjusted gross margin at a strong 51% in the quarter, this enhanced disclosure provides investors with greater visibility into AMETEK's margin performance and additional details to better understand our cost structure and the underlying drivers of our profitability. Going forward, we will provide an updated gross margin disclosure quarterly on our website. In summary, our businesses had a great start to the year. Our exceptional operating capabilities delivered excellent revenue and earnings growth, robust margin expansion, and strong free cash flow conversion. With a proven strategy, significant capital deployment capacity, and a strong track record of execution, we are confident in our ability to drive further growth and value creation in 2026.
I'll now pass it back to Kevin.
Great. Thank you, Dalip. Stacy, could we please open the line for questions?