Self-tapping fasteners

EJOT ALtracs® Plus

Optimised screw fastening of components subject to high stress. With the ALtracs® Plus screw for light metals.

 

Improved reliability for light metal joints

EJOT ALtracs® Plus helps to optimise processes and cut costs.

Less work, lower costs. By eliminating the need for production steps such as drilling, thread-cutting and cleaning, and optimising tooling, inventory stocks and cycle times, savings of up to 30% can be achieved. So it's hardly surprising that the demand for thread-cutting screws is on the rise.

Method / principle

Direct screwing connection without additional thread cutting that connects components safe and long lasting becomes possible due to the function of the EJOT ALtracs® Plus. Without the necessity of cutting a thread reduces tool costs and working time.

Applications

Thinner, lighter, better. EJOT ALtracs® Plus screws are the reliable, fast and cost-effective fastener for light metals.

Product benefits
  • Low loss of preload force under high dynamic and thermal loading
  • Excellent vibration resistance with no additional retainers
  • Low insertion torque for safe assembly
  • Repeat usage possible

Product benefits

There are many good reasons for using our products.

Strength and options.
Point by point.

Suitable for lightweight construction

The optimised thread geometry of the EJOT ALtracs® Plus enables smaller and shorter screws to be used, with no loss of strength.

Good reliability

Low loss of preload force. Stays in place even under high dynamic and thermal loading.

Very good vibration security

Even without the usage of additional safety elements the connection is extremely vibration resistant.

Process reliability

Very safe assembly. Low insertion torque values make the screws ideal for automated processes.

Metric internal thread

Repeat usage is possible. In addition, a metric screw can be used for servicing.

Assembly

 

Work steps

Compared to metric screws, specific work steps during the assembly process of the EJOT ALtracs® Plus screw can be left out. ​​​​​​​This leads to a reduction of the overall process and a more economical assembly becomes reality.

Work steps during the EJOT ALtracs® Plus assembly

Detailed description

 

Thread geoemetry

With a screw flank angle of 33° instead of 60°, the EJOT ALtracs® Plus achieves a higher connection strength, as it geometrically increases the load capacity of the nut thread. The smaller displacement volume of the 33° flank causes lower insertion torques.

  • Low material displacement due to small 33° flank
  • Larger nut thread tooth
  • Greater load capacity of each individual EJOT ALtracs® Plus thread
  • Shorter screw-in depth possible
EJOT ALtracs® Plus thread in detail

EJOT ALtracs® Plus screw

Thread in detail

 

33° thread

A flat load flank of 22° causes a large axial force component (preload force) and a low radial stress. The 11° back flank prevents premature failure of the thread flank at high preload forces. The tooth root reinforcement provides a stable connection of the thread flank to the screw core.

  • Small load flank of 22° generates high preload force
  • Additional stability due to 11° rear flank to absorb high preload force
  • Stable connection of the 33° thread flank to the screw core through tooth root reinforcement
EJOT ALtracs® Plus screw thread in detail

EJOT ALtracs® Plus screw

Thread in detail

 

In comparison: 60° thread

  • Smaller female thread tooth than EJOT ALtracs® Plus
  • Reduced load capacity of each individual thread
  • Greater screw-in depth necessary
Thread of a screw with 60° flank angle in detail

Thread of a screw with 60° flank angle in detail

 

Metric compatibility

During the assembly EJOT ALtracs® Plus forms a thread, which can be reused for metric screws. Should a repair or service be required, conventional screws can be installed without any difficulties.

Metric screw can be mounted into the thread grooved by EJOT ALtracs® Plus

Metric screw can be mounted into the thread grooved by EJOT ALtracs® Plus

 

Circular thread geometry

The large flank coverage results in higher pull-out forces. The circular contact surfaces in the thread result in higher self-locking and thus a higher screw-locking function. Because more thread flanks are in use, the acceptance of drill hole tolerances is higher.

  • Maximum flank overlap
  • Larger bore tolerances possible
EJOT ALtracs® Plus circular thread geometry

EJOT ALtracs® Plus screw

Circular thread geometry

 

Thread forming zone

  • Non-circular furrow zone
  • Simple and easy screw placement
  • Safe penetration into the material
  • Safe penetration of the possibly existing casting skin
EJOT ALtracs® Plus thread forming zone

EJOT ALtracs® Plus screw

Thread forming zone

Load capacity of the screw connection

 

EJOT ALtracs® Plus compared to metric screws

Load capacity of the screw connection in comparison – EJOT ALtracs<sup>®</sup> Plus (left) and metric screw (right)

EJOT ALtracs® Plus (left) and metric screw (right)

The EJOT ALtracs® Plus furrows a backlash-free nut thread in light metal. Paired with the geometrically strengthened nut thread tooth and the effect of work hardening during thread forming, a high load capacity of the screw connection is achieved, even under thermal stress. In addition, the formed EJOT ALtracs® Plus thread achieves a high dynamic safety due to the effective clamping torque, without additional measures such as polyamide coating, micro-encapsulation or under-head profiling.

The EJOT ALtracs® Plus offers the following characteristic values:

Compared to metric cable glands, strength class 8.8

  • Higher pretensioning forces
  • Therefore smaller screw dimensions may be applicable
  • Comparable long-term behaviour
  • Higher loosening torques
  • Greater axial extraction forces​​​​​​​

Compared to metric screw connection, strength class 10.9

  • Comparable prestressing forces
  • Comparable long-term behaviour
  • Higher loosening torques
  • Greater axial extraction forces
 

EJOT ALtracs® Plus compared to non-circular screws

Load capacity of the screw connection in comparison - EJOT ALtracs<sup>®</sup> Plus (left) and non-circular screws (right)

EJOT ALtracs® Plus (left) and non-circular screws (right)

Load capacity of the screw connection in comparison - EJOT ALtracs Plus (left) and non-circular screws (right)

The design of the ALtracs® Plus thread geometry results in optimal utilization of the material properties.

This means:

  • High installation safety because of high overtorque
  • High and constant preload forces due to reinforced nut thread flanks
  • Low creep tendency under thermal and/or dynamic load due to large thread overlap
  • Reduction of the screw-in depth possible, i.e. shorter screws, smaller components, less weight, more favorable wear conditions in the die-casting tool
  • Good repeat assembly property
  • High vibration resistance

Unlike other thread cross-sections, the ALtracs® Plus thread is fully engaged and fully loadable on its circular circumference.

This, together with the higher load capacity of the geometrically reinforced nut thread, leads to the following advantages in practice

  • Higher preload forces with shorter screw-in depths
  • Improved long-term behaviour (residual clamping force, dynamic safety)
  • Higher pull-out force
  • Castable bore tolerances

More information

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