Hi-Shear Rivet Pin Fastening Product Portfolio

Hi-Shear Fasteners are patented fasteners of Hi-Shear Corporation (Patent Holder), subsidiary of Lisi Aerospace, a manufacturer of advanced aerospace fasteners and installation equipment used in space, military and commercial vehicles. Depending on the fastener, they are made by quality fastener manufacturers (licensees) including but not limited to Lisi Aerospace companies, Howmet Alcoa / Simmonds / Fairchild, PCC  SPS, and others, in different  countries. 

Hi-Shear Corporation Hi-Lok™ (HL™) fasteners are the second most used fasteners in aircraft structural assembly after the solid rivets MS20470 and MS20426. The Hi-Lok™ fastener system includes a rivet pin (similar to a screw but with additional advantages) and a collar (similar to a nut). The main reasons/benefits of using this type of fasteners include:
1. Higher tension and shear strength, the material used and the geometry of the fastener provides the best properties regarding strength. Suitable for shear and/or tension applications, on plain or sloped surfaces
2. Lightweight fasteners, the Hi-Lok™ system offers the best relation between weight and strength regarding the assembly between two elements. Better that the use of screws and nuts.
3. Easy and quick assembly, with the specific tools the assembly time is must lower that the rivet or screws/nut assembly time. The assembly is very easy with no complex steps and the final assembly is always perfect with no defects. Suitable for clearance, transition and low interference fit installation.
4. Good stress concentration factor, the specific geometry of the pin element provides the hole with an increase in fatigue life, much better that if we use the screw/nut system.
5. Fastener cost, accessible and cost effective element in the installation on the aircraft.
6. Correct torque application, the collar property gives us the guaranty that the correct torque is applied to the assembly, removing the problem of vibration, strength and fatigue of the pin itself.
7. Wide variety of materials and coatings for installation in all structures.

Delivering high strength controlled preloaded system, the Hi-Shear Hi-Lok™ rivet pins are the original and versatile solution for strong and reliable assemblies. With a wide range of shapes, materials and coatings, they are suited for most of structural assemblies and are still commonly used in the aerospace industry for clearance, transition and low interference fit throughout the airframe (metallic and composite), from wings to fuselage, in engine fairings, and more. The HI-LOK™ series includes several type of rivet pins and collars, depending of the desired application with the HL18, HL19, HL20 and HL21 series being the most used ones.  The Hi-Lok™ rivet pins can be divided for use in tension and shear applications. The tension rivet pins, with greater heads than the shear pins, are selected when the main load applied is tension while the shear rivet pins when the shear is the dominant load. Rivet pins can be further divided in those with protruding or countersunk head.  For example, the HL18 series realte to shear protruding hed rivet pins, the HL20 are tension protruding head rivet pins, the HL19 are shear countersunk head rivet pins and the HL 21 are countersunk head pins.

The Hi-Lok™ series rivet pins can also be replaced by equivalent Hi-Lite™ (HST™) rivet pins, the direct evolution of Hi-Lok™ rivet pins, for improved weight saving. Combined with Hi-Lite™ nuts and collars, they provide up to 13% weight saving compared to the previous Hi-Lok™ generation. Both Hi-Lok™ and Hi-Lite™ rivet pins are also available with Aster recess (HSTR pins) for an improved recess that prevents failure during the assembly process,  especially suited for clearance fit assemblies of composite structures.

Hi-Tigue™ (HLT™) pin series are also offered featuring improved fatigue benefits by combining the hole-improvement qualities of the Hi-Tigue™ pins and the consistent preloading qualities of the Hi-Lok™ collars.

The P/N of Hi-Shear rivet pins is composed of sequencing letters and numbers indicating the type (series) of the pin, geometry, material and other information. For example, in the P/N HL18PB-5-16 the HL letters specify a HI-LOK™ fastener, the number 18 determines the geometry and material of the fastener, the letter PB defines the finish protection of the fastener, the -5 number defines the diameter of the fastener per multiples of 32in. ( diameter =5/32 =0,156 in) and the -16 defines the grip length of the fastener per multiples of 16 in.  (length = 16/16= 1 in).

Several Hi-Shear Hi-Lok™ (HL™) and Hi-Lite™ (HST™) fasteners can be used as alternates to EN6114 series which together with their EN6115 counterparts are commonly used on Airbus A320, A330, A350 and A380 aircraft. Airbus A320/ A330 aicraft commonly use the alloy steel version of the EN6114 series and the Titanium series indicated by the V and T coding. The new A350 and A380 designs incorporate Inconel material deliniated by the L and M coding. 

Hi-Shear Nuts & Collars

Hi-Shear nuts and collars are designed to fit with their related Hi-Lok™/Hi-Tigue™ and Hi-Lite™ pins  (separately presented) forming the respective fastener system. Hi-Lok™ nuts and collars are designed to fit Hi-Lok™ & Hi-Tigue™ pins. Hi-Lite™ nuts and collars are designed to fit Hi-Lite™, Pull-In™, Pull-Stem™ & Taper Hi-Lite™ pins.

With a wide range of shapes, materials and coatings, they are suited for most of structural assemblies and are commonly used in the aerospace industry in tension and shear applications. Collars’ wrenching element is designed to break-away at a controlled preload. It has been tested over time and has proven its reliability when installed with non-torque-controlled tools. Main features of nuts and collars include:
- controlled preload
- wide variety of materials and coatings for installation in all structures
- suitable for shear or tension applications, with captive washer, self-aligning or self-sealing options
- limited access installation, using conventional tooling
- designed with a counterbore to fit nominal and oversized pins
- nuts allow customized torque and preload & low height design for low access areas

For additional information please refer to the respective product presentations at our Web Platform for Supplies (shop.aviationeu.supplies).