Four years ago, we exposed the story of flimsy counterfeit bolts being used in the nation's buildings and bridges. As the scandal unfolded, we found that many more buyers -- from airlines to the Army -- had been sold low-grade bolts without realizing the merchandise was flawed.

Despite our warnings and some indictments, the nation is still at the mercy of bogus bolts and an attempt to regulate the bolt industry is faltering in Congress. A bill now in the Senate to require lab testing and registration of bolts has run into a fusillade of flak from the bolt distributors who would have to meet those new standards.

So far, no senators have knuckled under, but congressional sources say lawmakers are being lobbied heavily. It would take only one senator to derail the bill because unanimous consent is needed to pass the bill without a floor vote, and there is no time in the session's waning days for a floor vote.

We first reported in 1986 that substandard bolts from foreign manufacturers were being used in place of high-grade U.S. bolts in an array of structures. The substitutes are dangerously brittle or could loosen under the pressure of heat or strain.

Some factories in Japan, Taiwan and Korea are known to make cheap replicas of standard bolts used in this country. We have documented over the years how they have jeopardized everything from drawbridges and oil rigs to commercial airliners, nuclear power plants and Army tanks.

The bill, already passed by the House and pending in the Senate, would enhance public safety and please many U.S. bolt makers who want to clean up the market for their costlier but better bolts.

It's the middlemen who are putting up the stink. Distributors complain that they will spend a fortune tracking the bad bolts. When the Senate Commerce, Science and Transportation Committee endorsed the bill, distributors claimed the extra safeguards could cost them $800 million -- a figure viewed on Capitol Hill as wildly inflated.

It looks like a simple case of industry dragging its feet, and Houston bolt maker Tommy Grant agrees. Grant was one of the first to sound the alarm about bad bolts. "Distributors want {the law} watered down so they can continue business as usual," he told our associate Dan Njegomir.

The balking distributors bombarded the Commerce Committee with letters and phone calls. But the committee endorsed the bill anyway.

Now the pressure is on the full Senate. Indiana's delegation, for example, has been urged by some home-state bolt distributors to soften the bill, but the state's senior senator, Republican Richard G. Lugar, reportedly is happy with it as is.

The bill has already been hedged with an amendment to satisfy distributors' most common complaint about a provision against mixing batches of bolts from different sources. But even that concession has not stopped the distributors' whining.

"This is an industry that, with the exception of some of its leaders, hasn't come to grips with its problems," committee staffer Pat Windham told us.

So Congress must do that for the industry. Until then, lives quite literally will hinge on bad bolts.