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You Are Here: Home » Rivnut/Plusnut
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Rivnut® - The Original 
UNITED STATES PATENT OFFICE
2,149,199
TUBULAR RIVET "Rivnut® - The Original blind installed internally threaded rivet, was invented (patent #2, 129, 199) in 1936 for the purpose of attaching a rubber aircraft wing de-icer extrusion to the leading edge of the wing. The Rivnut® riveted the aluminum wing skin to the inner aluminum spar and then accepted a mating screw to attach the rubber de-icer. The Rivnut® fastener was given a military specification of MS27130 and an aerospace standard ofNAS1329 and NAS1330. Use of the Rivnut expanded within the military and aerospace markets, and soon became popular in general industry because of its many design and assembly advantages." 
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How the Rivnut® works: 1) Thread Rivnut® onto the tool mandrel, 2) place in the hole, 3) pull the tool trigger and the tool mandrel retracts causing the unthreaded portion of the Rivnut® to expand behind the parent material riveting itself in place. 
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Rivnut® - The Original
Design and Assembly Advantages - Installs blind in sheet metal, plastics and tubular materials.
- Can be used as a rivet to assemble two or more materials and as a nut for the attachment of a mating part with a screw.
- Installs into galvanized or pre-painted materials without damaging surface finishes.
- Installs mechanically without deforming the parent material.
- Installs with noncapital investment lightweight handheld pneumatic power tools at any location on an assembly line.
- Installs before or after a finish is applied to a product.
- Installs into material as thin as .020 (0.5mm) providing strong loadbearing threads.
- Installs at a rate of 20 pieces per minute with pneumatic power tools.
- Installs with inexpensive hand tools for field repair or consumer kit installation.
- Installs with semi-skilled labor with minimal training.
- Is ideal for automated assembly due to a balanced geometric shape.
- Installation is environmentally friendly and produces no harmful gasses, heat, dust or electromagnetic fields to affect workers.
- Installs into a wide range of material thicknesses due to a wide grip range tolerance.
- Meets Grade 5 and Metric class 8.8 mating screw proof loads.
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Rivnut® Application Information Optimum Joint Design - The parent material will be of a density and thickness to support the formation of the Rivnut's backside flange. Bollhoff suggests experimentation with various Rivnut® designs and grip ranges to determine the optimum joint design.
- Parent material closed shapes such as tubing or extrusions require enough backside clearance for the Rivnut® to be inserted fully before installation.
- The hole for the Rivnut® should be square to the parent material to assure a uniform backside flange formation. Hole size should be per the Rivnut® product tolerance and specification.
- The mating part should contact the head of the Rivnut® to assure optimum torque performance of the joint.
- Hole size in the mating part should be large enough for the mating fastener to enter the Rivnut® and allow the mating part to remain in contact with the head of the Rivnut®. Mating part hole formula should be screw diameter multiplied by 1.1. If the mating part hole needs to be enlarged for alignment purposes, use an elongated hole design to assure mating part contact with the head of the Rivnut®.
- The mating screw should be Grade 5 or Metric Class 8.8 strength. Rivnut fasteners are designed to meet the torque, tensile and clamp load requirements of these mating fasteners. Thread fit may be of 2A or 3A or Metric 6G design.
- The mating screw's thread length should engage all threads of the Rivnut® to assure optimum torque strength.
- If the application requires a mating screw with a nylon patch, micro-encapsulated adhesive, anerobic adhesive or other thread-locking mechanism, a Rivnut® Hex bodyfastener in a Hex hole will be needed to resist the prevailing torque created by the locking mechanism.
- Joint design for Rivstud® follows the same principles as mentioned above for Rivnut fasteners. Mating nuts should be of Grade 5 or Metric Class 8.8 or lower, and of a Class 2B or Metric 6H thread fit.
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Rivnut® Installation Information Power Tools - Parent materials or applications that vary in thickness require the use of the P 803. EPK or PNK Installation Tools for proper installation. The pressure pull feature of these tools will install the product in single, multiple or variable thickness materials. If torque-controlled tools are used, Rivnut® EZ fasteners are recommended and must have lubrication added.
- Parent materials and applications that are of a single material thickness can utilize either the P 803 or any of the stroke adjustable tools such as the P 330, C 302, and C 362. Tools adjustments for pressure and stroke are contained in the various Rivnut® tool manuals.
- Installation sequence is best done by threading the Rivnut® onto the tool fully and then inserting into the hole.
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