Investors looking for stocks in the Aerospace - Defense sector might want to consider either Embraer (ERJ Quick QuoteERJ - Free Report) or Northrop Grumman (NOC Quick QuoteNOC - Free Report) . But which of these two stocks offers value investors a better bang for their buck right now? We'll need to take a closer look.

Everyone has their own methods for finding great value opportunities, but our model includes pairing an impressive grade in the Value category of our Style Scores system with a strong Zacks Rank. 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, Embraer has a Zacks Rank of #1 (Strong Buy), while Northrop Grumman has a Zacks Rank of #3 (Hold). The Zacks Rank favors stocks that have recently seen positive revisions to their earnings estimates, so investors should rest assured that ERJ has an improving earnings outlook. However, value investors will care about much more than just this.

Value investors are also interested in a number of tried-and-true valuation metrics that help show when a company is undervalued at its 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.

ERJ currently has a forward P/E ratio of 18.93, while NOC has a forward P/E of 19.70. We also note that ERJ has a PEG ratio of 1.11. 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. NOC currently has a PEG ratio of 9.

Another notable valuation metric for ERJ is its P/B ratio of 0.66. 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, NOC has a P/B of 5.53.

Based on these metrics and many more, ERJ holds a Value grade of A, while NOC has a Value grade of C.

ERJ has seen stronger estimate revision activity and sports more attractive valuation metrics than NOC, so it seems like value investors will conclude that ERJ is the superior option right now.