by: Shuichi Amano Chief Engineer/Engineering Director Nissei Co., Ltd.
An invitation to look at a new solution to the old problem of bolt loosening — request to roll and
sell it under a licensing arrangement.
We might think there are no technical improvements left to be made on a bolt. But let’s think again
—what about the problem of loosening? It is a fact of mechanical life that bolts loosen. Many
techniques for keeping bolts tight have appeared. From the point of view of practical usage, cost
effectiveness and the ability to truly prevent loosening, making better bolts is an old, but new
Nissei invites you to look at its fresh solution, the PLBv2. PLBv2 (Perfect Lock Bolt, version 2) relies
on double nuts and multiple threads rolled onto a single shaft.
For fasteners such as bolts, loosening is the enemy. The need for periodic tightening and problems
arising when bolts need to be replaced or re-used is common. In the battle against loosening, many
solutions have been attempted—all, until now, mediocre. Relying on friction to prevent bolts from
loosening is not good enough. A mechanical solution built into the structure of the bolts is what is