Bow Hunting Broad Arrowhead

The arrowhead uses a pin as a pivot for two folding blades in the centre of the assembly. The application requirements are such that the pivot pin must not bend under impact, and it must allow the blades to pivot freely around it. The hunter must also be able to service the assembly in the field; therefore the pin must be able to be removed and reinstalled at least three times and still provide the necessary retention.

The original design incorporated the use of a Slotted Spring Pin as the pivot, but the Slotted Pins were bending upon impact resulting in a dysfunctional head which made the removal of the pin during servicing extremely difficult.  

Through a comprehensive evaluation of the design and serviceability requirements, SPIROL Engineering recommended a full length Helical Knurl Solid Pin (SPIROL Series KP300) manufactured from stainless steel for use in this assembly. By the nature of its design, this Solid Knurl Pin does not require tight tolerances on the ferrule’s holes for retention. The knurls of the pin remain securely engaged in the host material to ensure that the assembly stays intact during use. The Solid Pin also provides the necessary strength to eliminate bending upon impact. The SPIROL Helical Knurl Pin can be removed and reinstalled simply by using needle nose pliers and a small hammer or striking tool. An additional benefit of using this pin is that the clearance between the hole in the blades and outer diameter of the Knurl Pin is minimal which provides a very robust “feel” to the assembly.

SPIROL’s Helical Knurl Pin is the most cost effective solution for this assembly as it provides the required retention, resistance to bending, and the ability for the hunter to remove and replace it using basic hand tools.

Complimentary Applications Engineering Support: SPIROL Engineers will review your application needs and work with your design team to recommend the best solution.