The Dow Jones Industrials (DJINDICES:^DJI) kept its record-setting streak alive on Tuesday, gaining three points and just barely setting yet another all-time high. The index has put together an impressive long-term performance, yet some of the stocks that have helped lift the Dow to unprecedented heights aren't necessarily the first ones you'd think of. Let's look at how 3M (NYSE:MMM) and Travelers (NYSE:TRV) have quietly climbed to record levels of their own.

Source: 3M.

3M stock fell back a bit today, closing just below its all-time record close on Monday. Yet what has investors excited about 3M is the conglomerate's work to reinvigorate its renowned innovative spirit, exploring new avenues in its diverse businesses to come up with groundbreaking products. This week, 3M had to deal with the departure of its CFO to join a biotech company. But the depth of 3M's talent bench meant it already had a solid replacement with more than a quarter-century of experience at the company.

Meanwhile, from a longer-term perspective, 3M has enjoyed strong business results. The Dow component saw positive organic sales growth in its first quarter across the board, with the most strength in its health-care and industrial segments. 3M has had success around the world as well, with balanced growth contributing to investor security. Overall, 3M has been performing well internally, and its share price reflects that enthusiasm.

Source: Travelers.

Meanwhile, Travelers reached new heights today. The insurer also had to deal with some personnel changes recently, with the exit of its executive vice president for the business insurance division. That necessitated a minor reshuffling of roles within the company, dividing the former executive's roles across two different job descriptions.

Travelers owes most of its success to a lack of major catastrophic events recently. As hurricane season has just begun, that favorable record could change on a dime if a storm hits the U.S. mainland this year. Investors have started reining in their expectations for the insurance giant's earnings, resigning themselves to the idea that Travelers likely won't duplicate its stellar earnings performance from 2013. Still, as long as conditions remain relatively favorable for the blue-chip company, Travelers could continue to see share price gains this year and beyond.

As the Dow advances, be sure to watch out for its unsung winners. Often companies such as 3M and Travelers get the least attention but deserve the most credit.