Sifting through countless of stocks in the Machinery industry can be tedious, and sometimes two stocks are just too similar to judge which is the better investment. If you’re on the fence about investing in Flowserve Corporation, Proto Labs or Inc. because you’re not sure how they measure up, it’s important to compare them on a few factors before making your decision.

Read on to learn how Flowserve Corporation, Proto Labs and Inc. compare based on key financial metrics to determine which better meets your investment needs.

About Flowserve Corporation, Proto Labs and Inc.

Flowserve Corporation designs, manufactures, distributes, and services industrial flow management equipment in the United States, Canada, Mexico, Europe, the Middle East, Africa, and the Asia Pacific. The company operates in two segments, Flowserve Pumps Division (FPD) and Flow Control Division (FCD). It offers custom engineered pumps, pre-configured industrial pumps, pump systems, mechanical seals, auxiliary systems, replacement parts, and related services; and manufactures gas-lubricated mechanical seals for gas pipelines and in the energy production and process markets. The company also provides equipment services, including installation, commissioning services, seal systems spare parts, repairs, advanced diagnostics, re-rate and upgrade solutions, retrofit programs, and machining and asset management solutions. In addition, it offers engineered-to-order and configured-to-order isolation valves, control valves, valve automation products and related services and equipment; and actuators, positioners, and switches used to control, direct and manage the flow of liquids, gases and multi-phase fluids, and are a part of any flow control system. Further, the company provides equipment maintenance services for flow control systems, including advanced diagnostics, repair, installation, commissioning, retrofit programs, and field machining capabilities. It sells its products under the Valtek, Argus, Worcester, Limitorque, and Durco brands. The company serves oil and gas, power generation, chemical, water management and general industries, including pharmaceuticals, mining, food and beverage, steel, and pulp and paper industries. It distributes its products through direct sales, distributors, and sales representatives. Flowserve Corporation was founded in 1790 and is headquartered in Irving, Texas.

Proto Labs, Inc., together with its subsidiaries, operates as a digital manufacturer of custom parts in the United States and Europe. It offers manufacturing services, such as molding, computer numerical control machining, 3D printing, and sheet metal to developers, engineers, and supply chain teams. The company was incorporated in 1999 and is headquartered in Maple Plain, Minnesota.

Latest Machinery and Flowserve Corporation, Proto Labs, Inc. Stock News

As of October 9, 2026, Flowserve Corporation had a $9.2 billion market capitalization, compared to the Machinery median of $3.3 million. Flowserve Corporation’s stock is up 4.2% in 2026, down 2.8% in the previous five trading days and up 37.89% in the past year.

Currently, Flowserve Corporation’s price-earnings ratio is 25.2. Flowserve Corporation’s trailing 12-month revenue is $4.6 billion with a 8.0% net profit margin. Year-over-year quarterly sales growth most recently was -1.6%. Analysts expect adjusted earnings to reach $4.112 per share for the current fiscal year. Flowserve Corporation currently has a 1.2% dividend yield.

As of October 9, 2026, Proto Labs, Inc. had a $2.2 billion market cap, putting it in the 56th percentile of all stocks. Proto Labs, Inc.’s stock is up 85.5% in 2026, down 4.4% in the previous five trading days and up 86.64% in the past year.

Currently, Proto Labs, Inc.’s price-earnings ratio is 74.4. Proto Labs, Inc.’s trailing 12-month revenue is $560.5 million with a 5.4% net profit margin. Year-over-year quarterly sales growth most recently was 10.5%. Analysts expect adjusted earnings to reach $2.214 per share for the current fiscal year. Proto Labs, Inc. does not currently pay a dividend.

How We Compare Flowserve Corporation, Proto Labs and Inc. Stock Grades

Stock evaluation requires access to huge amounts of data and the knowledge and time to sift through it all, make sense of financial ratios, read income statements and analyze recent stock movements. AAII created A+ Investor, a robust data suite that condenses data research in an actionable and customizable way suitable for investors of all knowledge levels, to help investors streamline and work through such data.

AAII’s proprietary stock grades come with A+ Investor. These offer intuitive A‐F grades for each of five key investing factors: value, growth, momentum, earnings estimate revisions and quality. Here, we’ll take a closer look at Flowserve Corporation, Proto Labs and Inc.’s stock grades to see how they measure up against one another.

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Flowserve Corporation, Proto Labs and Inc. Stock Value Grades

Company	Ticker	Value
Flowserve Corporation	FLS	C
Proto Labs, Inc.	PRLB	F

Successful stock investing involves buying low and selling high, so stock valuation is an important consideration for stock selection.

Buying stocks that are going to go up typically means buying stocks that are undervalued in the first place, although momentum investors may argue that point.

AAII’s A+ Investor Value Grade derives from a stock’s value score. The Value Score is the percentile rank of the average of the percentile ranks of the price-to-sales ratio, price-earnings ratio, enterprise-value-to-EBITDA (EV/EBITDA) ratio, shareholder yield, price-to-book-value ratio and price-to-free-cash-flow ratio. The score is variable, meaning it can consider all six ratios or, should any of the six ratios not be valid, the remaining ratios that are valid. To be assigned a Value Score, stocks must have a valid (non-null) ratio and corresponding ranking for at least two of the six valuation ratios.

Stocks with a Value Score from 81 to 100 are considered deep value, those with a score between 61 and 80 are a good value and so on.

Flowserve Corporation has a Value Score of 41, which is Average. Proto Labs, Inc. has a Value Score of 14, which is Ultra Expensive.

The Value Stock Winner: No Clear Winner

Neither Flowserve Corporation, Proto Labs or Inc. has a high enough value grade to be considered a “winner.” Investors who are considering these companies should do additional due diligence and research to see if either could be a good addition to their portfolio. It’s important to look at a wide range of financial metrics in order to determine if Flowserve Corporation, Proto Labs or Inc. is the better investment when it comes to value.

Flowserve Corporation, Proto Labs and Inc.’s Momentum Grades

Company	Ticker	Momentum
Flowserve Corporation	FLS	B
Proto Labs, Inc.	PRLB	A

Momentum grades help to uncover stocks experiencing anomalously high rates of return; research finds that stocks with high relative levels of momentum tend to outperform, whereas those with low levels of momentum tend to continue underperforming. Momentum is based on the price change of a stock over a specified period relative to all other stocks.

Typically, AAII looks at the weighted relative strength over the trailing four quarters. The weighted four-quarter relative strength rank is the relative price change for each of the past four quarters. The most recent quarterly price change is given a weight of 40% and each of the three previous quarters are given a weighting of 20%.

Flowserve Corporation has a Momentum Score of 79, which is Strong. Proto Labs, Inc. has a Momentum Score of 90, which is Very Strong.

The Momentum Grade Winner: Proto Labs, Inc.

As you can clearly see from the Momentum Grade breakdown above, Proto Labs, Inc. is considered to have stronger momentum compared to Flowserve Corporation. For those specifically looking for companies that have stronger momentum compared to other companies in the same industry, Proto Labs, Inc. could be a good stock to invest in. However, it’s important for investors to analyze multiple factors based on a wide range of metrics before deciding whether to buy.

Flowserve Corporation, Proto Labs and Inc.’s Estimate Revisions Grades

Company	Ticker	Earnings Estimate
Flowserve Corporation	FLS	C
Proto Labs, Inc.	PRLB	B

Earnings estimate revisions scores consider the magnitude of a company’s earnings surprise in its last two reported fiscal quarters. Often, positive surprises beget further positive surprises‐or at least continued sales growth (the exact opposite is generally true, too).

Estimate revisions offer an indication of what analysts are thinking about the short-term prospects of a firm. Estimate revisions are based on the statistical significance of a firm’s last two quarterly earnings surprises and the percentage change in its consensus estimate for the current fiscal year over the past month and past three months.

Flowserve Corporation has a Earnings Estimate Score of 57, which is Neutral. Proto Labs, Inc. has a Earnings Estimate Score of 73, which is Positive.

The Earnings Estimate Revisions Grade Winner: Proto Labs, Inc.

As you can clearly see from the Earnings Estimate Revisions Grade breakdown above, Proto Labs, Inc. has a better Earnings Estimate Revisions Grade than Flowserve Corporation. For those who are specifically looking for companies with better short-term prospects when compared to other companies in the same industry, Proto Labs, Inc. could be a good stock to invest in. However, it’s important to analyze multiple factors based on a wide range of metrics before deciding whether to buy.

Other Flowserve Corporation, Proto Labs and Inc. Grades

In addition to Estimate Revisions, Momentum and Value, A+ Investor also provides grades for Growth and Quality.

Growth investing builds on the idea that stocks of companies exhibiting strong, consistent and prolonged growth outperform those of slower-growth companies. AAII measures growth through consistency of annual sales growth, five-year sales growth rankings adjusted for extreme levels, and consistency of positive annual cash from operations.

AAII’s A+ Investor Quality Grade comes from the ranking of key metrics. Specifically, the quality grade is the percentile rank of the composite of return on assets (ROA), return on invested capital (ROIC), gross profit relative to assets, buyback yield, change in total liabilities to assets, accruals, Z double prime bankruptcy risk (Z) score and F-Score.

These 2 key factors, when combined with the above, provide a holistic view into a particular stock. Further, by joining A+ Investor you can see whether Flowserve Corporation, Proto Labs and Inc. pass any of our 60+ stock screens that have outperformed the market since their creation.

So, Which Is the Better Investment, Flowserve Corporation, Proto Labs or Inc. Stock?

Overall, Flowserve Corporation stock has a Value Score of 41, Momentum Score of 79 and Estimate Revisions Score of 57.

Proto Labs, Inc. stock has a Value Score of 14, Momentum Score of 90 and Estimate Revisions Score of 73.

Comparing Flowserve Corporation, Proto Labs and Inc.’s grades, scores and metrics can act as a solid basis to determine whether they may be a good investment or not. You’ll also want to look at your portfolio’s asset allocation as well as your risk tolerance and financial goals to see if either of these stocks would make a good fit for you. AAII can help you figure out which investments align with your individual needs and preferences.

Investors are encouraged to do their own due diligence and research. In this way, individuals can effectively become managers of their own assets‐without having to rely on others for financial independence. You can count on AAII for timeless articles on financial planning and stock-picking, unbiased research and actionable analysis.

A+ Investor adds to our qualitative teaching with a powerful data suite to help you whittle down investment choices to find stocks, exchange-traded funds (ETFs) or mutual funds that meet your needs.

AAII Disclaimer

We make no representations or warranties that any investor will, or is likely to, achieve profits similar to those shown, because past, hypothetical or simulated performance is not necessarily indicative of future results. Before making an investment decision, you should consider your circumstances and whether the information on our content is applicable to your situation. This information was prepared in good faith, and we accept no liability for any errors or omissions. The full disclaimer can be read here.