Among the elaborate seals, bronze statues and marble hallways that adorn federal Washington, there is another symbol of the machinery of government that is often overlooked: the lowly ballpoint pen.

For more than 40 years, standard black pens have cluttered the desks of thousands of federal employees, hung on a chain at post offices across the country and slipped into the pockets of countless military personnel. Yet few have realized that this government-issue pen has a history to rival that of any monument.

Blind workers assemble the pens in factories in Wisconsin and North Carolina under the brand name Skilcraft as part of a 72-year-old legislative mandate. The original 16-page specifications for the pen are still in force: It must be able to write continuously for a mile and in temperatures up to 160 degrees and down to 40 degrees below zero.

It has been used in war zones and gas stations, and was designed to fit undetected into U.S. military uniforms. According to company lore, the pen can stand in for a two-inch fuse and comes in handy during emergency tracheotomies.

"It's the Coca-Cola of ink pens," said Richard Oliver, operations manager at Industries of the Blind in North Carolina. "Everybody recognizes this pen."

The unassuming pen stamped with the words "SKILCRAFT U.S. GOVERNMENT" in white letters has endured despite quantum leaps in communications technology that have rendered lesser tools obsolete. Taking over from the fountain pen, it has withstood the advent of the rubberized "comfort grip" and the freely flowing gel ink, not to mention computers, instant messages and smartphones. The U.S. Postal Service alone orders 700,000 a year.

Annual production at the Greensboro, N.C., plant has dropped during the past two decades from 21 million pens to about 4 million, but it remains a bestseller among Skilcraft's office supplies.

The National Industries for the Blind is trying to keep it that way by reminding federal agencies that it is the official ballpoint pen supplier to the federal government, even if agencies sometimes buy from other suppliers. The group has been advertising its products and workers with posters and radio and newspaper spots, and it plans to hold a workshop for 1,500 procurement officers in May.

"It's still a cornerstone," said Kevin Lynch, chief executive of NIB, an Alexandria nonprofit organization that helps to coordinate production of the pens. "It's a dependable product."

Perhaps that is because, like the bureaucrats who use it, the pen is more performance than pageantry. The original design -- brass ink tube, plastic barrel not shorter than 4 5/8 inches, ball of 94 percent tungsten carbide and 6 percent cobalt -- has changed little over the decades. It costs less than 60 cents.

The pen's roots date to the Depression. The 1938 Wagner-O'Day Act required the federal government to buy certain products made by the blind, thereby creating jobs for a then-marginalized population. First came mops and brooms, but the program eventually expanded to include a full line of cleaning and office supplies under the brand name Skilcraft. In fiscal 2009, the program, now known as AbilityOne, raked in a record $658.5 million in sales of products and services.

The pens account for about $5 million in sales each year. About 60 percent of business is from the military, but the Agriculture, Commerce and Justice departments are all reliable customers, according to NIB. The pens are primarily issued through government agencies, though civilians can buy them by request through some retail stores.