This CRES fastener for a new product design in an airframe latch involved three different geometric challenges: a convex head feature, a reverse hex extrusion, and a rolled thread over a backward extrusion.
Sussex Wire created the convex head and hex-shaped reverse extrusion by cold forming the part in the first part of the process. As a result of the cold forming process, the hex created by the reverse extrusion created a stronger part than would have been possible by other means, such as machining, which would have significantly weakened the part. Sussex set up a secondary process to thread-roll the part without collapsing the hex cavity.
Use: Fasteners for Aerospace Industry
Material: Incoloy A-286
Manufacturing Method:
- Cold Heading
- Extrusion
- Reverse Extrusion
- Annealing
- Roll Forming
Critical Tolerances:
- Inset Hex Depth and Concentricity
- Head Height and Radius
- 8-32 Thread to AS8879, UNJC-3A
Advantages:
- 100% Net Shape – No material scrap
- Work hardened head-to-shank interface
- Work hardened threads per AS8879
- Final tensile at 130,000KSI, from original material tensile of 85,000 KSI
- Burr and silver free condition without mechanical secondary operation
- High throughput, low cost alternative to machining
