Screwbolt Bottom Plate Solutions

2020 Supply issues solved by Screwbolts

Demand for building products has taken off. With kiwis unable to travel, money is being spent on housing and renovations at record levels. This demand combined with chaos at the wharfs means supplies are under strain.

Bottom Plate anchors are a staple part of any new home or renovation build and are also effected.

For Decades the standard solution has been a Throughbolt, otherwise known as a Wedge Anchor. This is a simple "drill then hammer in" fixing. An expansion anchor that by design is not ideal for a close to edge application.

Screwbolts are a superior alternative

Screwbolts provide superior loads in close to edge applications and have many other benefits such as:

  • Full head marking for inspection and traceability.
  • Removable, adjustable and reusable.
  • They are non expansion anchors and therefore they do not pre load the substrate.
  • Hex bolt head which means they can be set with a Power Tool for faster install.

The Screwbolt Bottom Plate range has been available for over 10 years and comes with painted colour heads. This makes choosing the right anchor by application that much easier, while assisting with inspection when required.

Screwbolts provide higher load capacities by diameter compared to Throughbolts.

Reducing the diameter allows for better edge distance performance while improving install time.

All Bottom Plate Screwbolts are High Tensile grade Steel with a Mechanical Galvanised finish.

Full third party test data on the Screwbolt was completed by Swinburne University Melbourne Australia. Available here

Screwbolt Bottom Plate versions

The Bottom Plate Screwbolt range is divided up into three colour groups. Blue, White and Black. Each serving it's own particular purpose.

Blue Head Screwbolts are M10. This size provides adequate loads for all applications including 15kN Bracing perimeter, 7kN perimeter and 2kN internal.

Blue Heads come in three lengths.

  • 140mm Screwbolt for single Bottom Plate.
  • 150mm Screwbolt for single Bottom Plate including packer (up to 12mm).
  • 200mm Screwbolt for Double Bottom Plate Bracing.

White Heads Screwbolts are M8 x 140mm. White Head Screwbolts come in only one length, 140mm. This size is suitable for 7kN perimeter fixing.

Black Head Screwbolts are M8 x 100mm. Like the White Head Screwbolts, Black Head Screwbolts also only come in one length, 100mm. This size is suitable for 2kN internal fixing.


In conclusion, Screwbolts are far superior to Throughbolts as a Bottom Plate fixing. They are stronger and far easier to install.