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Monobolts - Flush Break Fasteners - Ullrich Fasteners Catalogue

Monobolts are high performance flush break fasteners designed to build-in strength, security, quality and cost saving benefits for the most demanding requirement. Fast and simple to install, Monobolts are ideal for original structural assembly and to replace conventional fastening methods, particularly when access to the workpiece is difficult.

For applications where speed, high strength joints, vibration and moisture resistant characteristics are essential, Monobolts are unrivalled. Monobolts enhance product quality and reduce assembly costs.

Monobolts are a precision engineered two-part component, developed from a highly successful product designed to meet stringent aerospace specifications and standards, including B.S. 5750. The fastener consists of a body and a stem and is supplied to the uses as a one-piece assembly.

A sealing land on the Monobolt stem provides exceptional resistance to moisture, an essential; requirement for many applications. The vibration resistant qualities of Monobolts has been tested and verified by independent laboratory tests conducted in accordance with a U.S. Aerospace Specification (NAS 1900). Monobolts are available in Aluminium Alloy, Carbon Steel and Stainless Steel, in diameters of 3/16” (4.8mm) and ¼” (6.35mm). Universal and Countersunk head configurations are also available.



Placing Sequence

  1. The Monobolts are placed in the prepared holes in the workpiece
  2. On actuation the tool jaws grip the Monobolt stem and exert an axial pull to give a high clench joint and complete hole fill
  3. The placing tool automatically breaks the stem flush with the head profile and mechanically locks the stem to the Monobolt body.

Installation Equipment

Monobolts are easily and speedily placed with their tooling equipment. The high speed 749,724 and 734 pneumatic power tools are ideal for applications requiring rapid fastener and placement and the robust 7540 hand tool is the alternative for less demanding assemblies.

Visible Lock

A major feature of the Monobolt construction is the unique visible locking element. In addition to providing positive stem retention, high strength performance and correct locking, this feature allows easy and visible inspection after placement.

Benefits of Monobolts (Flush Break Fasteners)


  • Monobolts are easily placed from one side of the workpiece
  • Simple high-speed fastening – takes on 1 ½ seconds to install Monobolts
  • Positively locked stem provides secure high strength joint
  • Visible lock allows quick and easy inspection
  • Eliminates two-piece fasteners


  • Choice of Aluminium Alloy, Carbon Steel and Stainless Steel.
  • Wide grip range from .064” (1.63mm) to .625” (15.8mm)
  • Monobolts may be used anywhere on the assembly line
  • Design flexibility provided by vibration and moisture resistant characteristics
  • Stem and body are plated with non-toxic zinc to withstand rust and corrosion
  • Choice of pneumatic placing equipment and hand tools

Monobolts for cost saving

  • Use monobolts for productivity, efficiency, lower cost and improved product quality
  • Monobolts reduce operator error and stockholding requirements.
  • These tools are made of the highest quality material for a long and reliable working life.
Ullrich Aluminium Australian Aluminium Council Ltd