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What is the Difference Between Torx and Torx Plus

As previously noted - the original Torx drive system was developed by Camcar Textron in 1967. But this early specification has undergone some beneficial development and improvement highlighted in this post.

Drive System Issues in Production

The drive systems used by various fasteners have a huge impact on productivity and product quality. For example, an inefficient drive system will increase assembly time and therefore eat into profitability.

Here’s a summary of just some of the issues associated with various typical, commonly used drive systems.

Hex Drive

Hex drive fastenings are very well known. A hexagonal socket in the head of a screw mates with a hexagonal tool (Allen wrench) to tighten or undo the screw.

While this style of drive system allows high torque transmission it is prone to early failure. When rotational pressure is applied to the tool this is transferred to the points of contact between the hex tool and the drive socket in the screw head. This localised pressure tends to round off the tool resulting in damage to both the tool and the fastening.

Cruciform Drive

Sometimes called cross-head, cruciform drives include the well known Phillips and Pozidrive.

Drivers self align with drive sockets due to the sloping sides of the drive sockets. But driving forces act to push the driver out of the socket (camout) due to these sloping sides. This means that additional pressure is required to keep the driver in the socket which has an impact on wear and tear as well as worker fatigue. Poor tool engagement reduces torque transmission and can result in concentrated stress which will potentially damage the driver or the fastening.

Slotted Drive

Slotted screw heads which accept flat-bladed screwdriver bits are very familiar. This style of screw and driver is not appropriate for automated assembly as tool alignment is not automatic.

Key failings with the slotted drive system include tool misalignment due to the slot head being open at both ends. This will damage the driver bit and the fastening. Torque transmission is limited due to tool misalignment in the slot. The nature of this design makes it susceptible to slippage and the damage that this can cause.

Torx Drive

The original Torx specification uses a six point star shaped socket recess in screw heads with a matching Torx screwdriver bit.

A key advantage of the Torx system is that is allows higher torque transmission than other drive systems enabling fastenings to be tighter and therefore more secure.

The straight sides of the Torx six sided star shaped socket helps prevent camout and require lower end-load than cruciform systems. But wide tolerances can present a loose fit between the driver tool and the screw head socket and the 15 degree drive angle can reduce the tool bit life.

Torx Plus Drive

As shown, Torx clearly outperforms other drive systems when considering factors of importance in production environments. But Torx is far from perfect which is what led to the development of Torx Plus.

Torx Plus addresses the limitations of the existing Torx system to provide optimal torque transfer and maximises tool lifetime.

Here are the key features of Torx Plus along with their benefits:

• Elliptically based geometry
  • Eliminates damaging point-to-point contact
  • Maximises the engagement of driver and recess
• Zero degree drive angle
  • Almost eliminates radial stresses and increases tool life
  • Optimises torque transmission
  • Allows the use of thinner walled recesses
• Lobes with large cross-sectional areas
  • Maximises torque transfer
  • Supports fast tool engagement
• Vertical sidewalls
  • Virtually eliminates camout
  • Ensures proper torque transfer
  • Massively reduced end load requirements
  • Increases tool engagement
  • Minimises tool slippage and resulting damage
  • Helps reduce fatigue and stress during manual assembly operations
• Enormously increased strength and reliability
  • Average bit life increased by 100%
  • Increased bit strength supports higher removal torque capability
• Compatible with Torx Drive
  • Torx Drive tools can be used to remove and reinstall Torx Plus recess fasteners.

The Torx Plus Drive system was developed to improve assembly line performance. Alignment difficulties between drive bits and recesses can slow down production lines. The Torx Autosert feature guides the driver bit accurately into the recess creating a self-centering engagement action.

Torx Plus is designed for high torque transmission. This means that higher torques can be used to securely tighten fasteners without incurring additional wear and tear on the tools. High torque capability is also very important in service situations where corrosion may increase the torque required to loosen a fastening.

Tamper Resistant Torx Plus Drive

The tamper resistant Torx Plus Drive variant (security Torx) uses a pentalobular (five point) design with a solid security pin at the centre of the recess. All of the Torx Plus benefits are included in the tamper resistant version along with additional security provided by the 5 lobe design with a central security pin.

Without doubt, Torx plus provides valuable improvements that help ensure that production lines run smoothly and efficiently while delivering tangible savings. And the highly secure Tamper Resistant Torx Plus drive design provides robust and reliable security.

If you need any help selecting the best security fasteners for your needs - please give us a call on 01273 475 500 - we are always happy to help.

This message was added on Monday 4th November 2019