Investors with an interest in Manufacturing - General Industrial stocks have likely encountered both Parker-Hannifin (PH) and Idex (IEX). But which of these two stocks is more attractive to value investors? We'll need to take a closer look to find out.We have found that the best way to discover great value opportunities is to pair a strong Zacks Rank with a great grade in the Value category of our Style Scores system. The Zacks Rank is a proven strategy that targets companies with positive earnings estimate revision trends, while our Style Scores work to grade companies based on specific traits.Currently, Parker-Hannifin has a Zacks Rank of #2 (Buy), while Idex has a Zacks Rank of #3 (Hold). Investors should feel comfortable knowing that PH likely has seen a stronger improvement to its earnings outlook than IEX has recently. But this is just one factor that value investors are interested in.Value investors also tend to look at a number of traditional, tried-and-true figures to help them find stocks that they believe are undervalued at their current share price levels.The Style Score Value grade factors in a variety of key fundamental metrics, including the popular P/E ratio, P/S ratio, earnings yield, cash flow per share, and a number of other key stats that are commonly used by value investors.PH currently has a forward P/E ratio of 12.68, while IEX has a forward P/E of 24.18. We also note that PH has a PEG ratio of 1.41. This metric is used similarly to the famous P/E ratio, but the PEG ratio also takes into account the stock's expected earnings growth rate. IEX currently has a PEG ratio of 2.02.Another notable valuation metric for PH is its P/B ratio of 3.55. The P/B is a method of comparing a stock's market value to its book value, which is defined as total assets minus total liabilities. By comparison, IEX has a P/B of 4.87.These are just a few of the metrics contributing to PH's Value grade of B and IEX's Value grade of D.PH is currently sporting an improving earnings outlook, which makes it stick out in our Zacks Rank model. And, based on the above valuation metrics, we feel that PH is likely the superior value option right now. Zacks Names "Single Best Pick to Double" From thousands of stocks, 5 Zacks experts each have chosen their favorite to skyrocket +100% or more in months to come. From those 5, Director of Research Sheraz Mian hand-picks one to have the most explosive upside of all. It’s a little-known chemical company that’s up 65% over last year, yet still dirt cheap. With unrelenting demand, soaring 2022 earnings estimates, and $1.5 billion for repurchasing shares, retail investors could jump in at any time. This company could rival or surpass other recent Zacks’ Stocks Set to Double like Boston Beer Company which shot up +143.0% in little more than 9 months and NVIDIA which boomed +175.9% in one year.Free: See Our Top Stock and 4 Runners Up >>Want the latest recommendations from Zacks Investment Research? Today, you can download 7 Best Stocks for the Next 30 Days. Click to get this free report ParkerHannifin Corporation (PH): Free Stock Analysis Report IDEX Corporation (IEX): Free Stock Analysis Report To read this article on Zacks.com click here. Zacks Investment Research