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Exploring Anti-Back-Out Technology for Upside-Down Automatic Bolt Tightening

Time:2025-08-26

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In modern industrial production, automatic bolt tightening is a common process. Among its many operation modes, the “bottom-up” (upside-down) tightening scenario is particularly troublesome: gravity tends to make the screw back out or even fall, which hurts both productivity and product quality. This article discusses several effective solutions, with references to Danikor’s technical applications in this area.


Optimized Use of Blow-Feed Modules

The blow-feed module is the mainstream way to deliver screws in automatic tightening systems. Compressed air blows the screw from the feeder to the front of the tightening tool. When tightening from the bottom up, however, the screw can retreat under its own weight once it reaches the target position. To solve this, a blow-feed module with a “Hold-screw” mechanism can be adopted.

The core of the Hold-screw mechanism is its clamping jaws, which ensure the screw stays perfectly vertical and stable. In addition, the distance the screw protrudes beyond the jaws is critical: a suitable protrusion allows the screw to enter the hole smoothly, preventing tightening failures caused by misalignment.

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Application of Vacuum-Suction Modules

In applications where interference prevents a blow-feed module from working, the vacuum-suction module becomes an ideal alternative. It uses vacuum suction to hold the screw at the tip of the tightening tool. Key success factors are the concentricity and perpendicularity of the suction.

Danikor employs advanced design techniques in its vacuum-suction modules. The nosepiece is manufactured with strict machining processes to guarantee both concentricity and perpendicularity during pickup. This design not only keeps the screw stable during bottom-up tightening but also improves tightening accuracy. Precise control of the vacuum force effectively prevents the screw from backing out or dropping during the process.

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Danikor’s Experience

Danikor has extensive experience and cutting-edge technology in automatic bolt tightening. Both its blow-feed and vacuum-suction modules undergo rigorous testing and optimization, providing reliable solutions to the back-out problem in upside-down tightening. Danikor’s engineering team can also offer customized solutions tailored to specific customer requirements, ensuring process efficiency and stability.


In practice, Danikor’s modules have gained recognition from numerous manufacturers. By adopting Danikor’s technology, companies have increased production efficiency and reduced quality issues caused by screw back-out. These success stories underscore Danikor’s professionalism and reliability in the field of automatic bolt tightening.


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