There’s Wall Street, and then there’s the “Wallflowers.” These are companies that go out of their way to avoid the Wall Street banking-and-research mill, content to let their businesses speak for themselves. Some companies end up as Wallflowers even if they prefer otherwise. They have been simply unable to get analysts to pay attention to them, perhaps because they don’t have the financing needs that can generate big fees for Wall Street banks.

You can also blame it on shrinking research departments in many financial institutions. The big firms have sought to reduce the number of companies they follow sharply, while a number of smaller financial firms have gone out of business altogether.

To me, this just spells opportunity.

As these companies toil in anonymity, they are still seeking ways to build sales and profits. Their shares may not reflect these efforts right now, but for the patient investor, unrealized shareholder value gets unlocked, one way or another.

Here are three Wallflowers worthy of further research.

1. NL Industries (NYSE: NL)
With a market value of almost $600 million and a consistent 50-cent annual dividend (good for a 4.2% yield), you would think this maker of various metal products would have had at least some sort of following on Wall Street.

Well, this company’s anonymity has been noted far away from Wall Street, in Texas to be exact. That’s the home of mega-investor Harold Simmons, who has been quietly building an ever-larger position in this company. Since mid-May, he has acquired another 20,000 shares and now controls more than 42 million shares, or roughly 90% of the company’s entire stock.

As is typical of many Wall Street Wallflowers, NL Industries has little communication with the investment community, so analysts don’t have much of an idea about current business trends or long-term goals. Interlocking relationships with other Simmons-controlled ventures such as Valhi (NYSE: VHI) and Kronos Worldwide (NYSE: KRO) can also create a bit of work for investors to untangle. Still, Simmons has an incentive to attract investor interest — shares have fallen from $18 a year ago to a recent $11.75, a level that is too low, if Simmons’ steeped up insider-buying is any indication.

2. Ingles Markets (Nasdaq: IMKTA)
With roughly $3.5 billion in annual sales, this Wallflower has a lot more heft than the lack of analyst interest may imply. To be sure, the North Carolina-based grocery chain has seen profit margins pressured in the face of Wal-Mart’s (NYSE: WMT) aggressive pricing moves.

Still, Ingles managed to deliver decent profit metrics, roughly in the mid-pack of the field. It’s unfair to compare this stock with industry darling Whole Foods (NYSE: WFM), which carries very rich valuations. It’s also unfair to compare it with industry laggard Supervalu (NYSE: SVU), which has seen its stock price crumble in the face of onerous debt burdens. Perhaps a comparison with industry mid-tier player Kroger (NYSE: KR) is more apt.

Ingles, which is focused more closely on one region of the country — the Southeast — appears to be the leaner operator. The company’s operating margins in 2011 were more than twice as high as that of Kroger’s. This may help explain why Ingles can afford to pay a much juicier dividend than Kroger. Value investors may note that Ingle’s trades for less than tangible book value, a claim that Kroger can’t come close to making.

Ingles is prepping to nearly double its warehouse capacity, which should enable a wide range of goods that are currently delivered by third-party vendors to be delivered in house. This could help push margins even higher.

3. Key Tronic (Nasdaq: KTCC)
Contract manufacturing, which involves making products for other companies, is a tough business. Just ask this company, which typically makes due with operating margins in the mid single digits.

Yet, even the toughest businesses can yield enough profits to attract investors’ attention. Thanks to a spate of new business wins, Key Tronic is posting solid growth metrics. Sales in the first nine months of fiscal (June) 2012 are up 33% to $96 million, compared with the same period last year, while earnings per share hit 74 cents. For the full fiscal year, the company appears on track to exceed the 97 cents a share earned back in fiscal 2006. (Actual fourth-quarter results are set to be released on Aug. 21).

This is a clear case of a stock’s anonymity pressuring its value. The entire company trades right around tangible book value, and for less than eight times likely fiscal 2012 profits. With 2,000 employees in plants spread across United States, Mexico and China, Key Tronic appears to be faring well in a tough economy, and could really flourish when the global economy strengthens.

Risks to Consider: As these companies tend to have limited communications with analysts, quarterly results can sometimes be far from what is expected. Make sure you research these stocks carefully.

Action to Take –> These Wallflowers build their businesses away from the treadmill of Wall Street’s quarterly expectations. The key is to find them when they slip to or fall below book value, as is the case with Ingles and Key Tronic. Another suggestion is to wait until they’re propped up by other catalysts, such as significant insider buying, as is the case with NL Industries.