The board also raised the quarterly dividend 12%.
The Winona, Minn., company earned 34 cents a share in the quarter compared with 31 cents in the year-earlier quarter. Revenue reached $1.36 billion from $1.28 billion.
Analyst estimates varied. Bloomberg News' survey pegged the consensus at earnings of 33 cents a share on revenue of $1.34 billion. FactSet's survey called 35 cents and $1.4 billion.
At last check Fastenal shares were trading off 4% at $48.42.
The revenue rise reflected continued demand for personal protective equipment and sanitizer products "to mitigate the impact of the coronavirus pandemic, support resumption of manufacturing and construction activity, and support sales to new customers," the company said.
"Growth of our product lines other than safety and janitorial, including fasteners, remained negative relative to the fourth quarter of 2019, but improved versus the third quarter of 2020 and through the fourth quarter of 2020, during which we continued to see gradual sequential improvement in general business activity."
Chief Executive Daniel L. Florness said in a statement that ["safety] has overperformed over time, providing about 26% of our growth in the two years from 2017 to 2019 despite being less than 20% of sales.
"In 2020, amid economic contraction and a covid-linked surge in PPE demand, its contribution swelled to 156%. Our presence and capabilities in safety allowed us to serve, highlighted our 'problem solving' culture, and should open up new customer and end market opportunities to us."
For the fourth quarter Fastenal said it paid both its regular dividend of 25 cents a share and a special dividend of 40 cents, with the latter reflecting "high cash balances and favorable financial outlook."
For the first quarter Fastenal declared a dividend of 28 cents a share, payable March 3 to holders of record Feb. 3.
Fastenal has more than 2,000 stores around the country, used by small and large businesses needing to stock their manufacturing facilities.