Alcoa Markets All :

GP® High Strength Tension Stump Type Lockbolts

Titanium GP™ Stump-Type Lockbolts

GP™ High Strength Tension Stump Type Lockbolts
Huck's (GP™) Lockbolt fastener is a high-strength aerospace fastener. Easily one of the most cost-effective high strength aerospace fastener available, the GP™ can help reduce aircraft weight due to the use of aluminum collars instead of steel collars or nuts used on threaded fasteners to achieve full tension values.
The GP™ stump Lockbolt  is designed for use in automated applications in both interference and clearance fit conditions. Common applications include wing spars, stringers, webs, fuselage panels and major joins.
The GPS is a high strength version of the Huck Lockbolt family used on aircraft for over 50 years. The GPS is available in protruding head, 100° flush MS24694 full tension head, 100° flush MS20426 tension head and modified head versions for special applications unlike threaded fasteners, lockbolts install rapidly and cannot vibrate loose. Their unique design assures predictable, consistent clamp force.
Design Features


The GP™ stump Lockbolt  features a tapered root diameter and variable pitch lock groove. A larger volume of collar material flows into the locking grooves at the beginning of the of the installation sequence. This gives the fastener its greatest tensile strength where it is most crucial during swaging of the collar so that a high clamp force can be developed with out loss of strength during collar swaging/extrusion resulting in a high residual clamp and high ultimate tensile. The locking groove’s 20-degree flank angle serves as a platform for retaining the high clamp load generated during collar installation.
Cost effective Features
Sloped surface installations
The GP™ stump Lockbolt can be installed on sloped surfaces up to 7° on the collar side of material being fastened.

With this feature heavy, costly self-aligning washers and special nuts are not required. Inventory costs as well as structural weight is reduced. Fewer parts to handle translate into greater labor efficiency.
Extended grip range
The GP™ stump Lockbolt has a usable 3/32" grip range, which reduces inventory, and installation errors that are common when using conventional 1/16" grip range fasteners. The extended grip range makes the GPS fastener more forgiving if the installer needs a fastener just over or just under the recommended grip.
The labor-intensive job of over-coating each fastener or the use of heavy, costly sealing nuts is eliminated with the GPS fastener. Annular grooves on the pin forms a series of separate barriers to prevent fuel seepage. Fay surface sealant flow during installation due to high clamp load ensures reliable sealing.
Automated installations
Huck offers a variety of collar feed systems for use on drill riveter machines to enhance automated applications. Equipment for use on flat stock or deep pocket applications, as well as normal offset tooling for clearance applications. Additional Huck provides a complete service representative to assist in set up and operation of automated systems.

Viewing documents in PDF format requires Adobe Acrobat Reader, which is available as a free download from the Adobe Web site.

Related Documents
How to Order [33KB]

Related Information

Mechanical Properties

Technical Information

Engineering Standards

Contact Information
Find out more information about this product