This ARP header nut features a large flange head for extra clamping surface, a 5/16-24 thread, and a 3/8in 12-point head for wrench access in tight header collector areas. It's machined from chromoly steel with a black oxide finish.
Specifications:
- 5/16-24 in Thread
- 3/8 in 12-Point Head
- Large Flange
- Chromoly Construction
- Black Oxide Finish
- Sold Each
FAQ
What thread does this nut have?
It has a 5/16-24 thread.
What size is the head?
It has a 3/8in 12-point head.
What makes it a 'large flange' nut?
It has an enlarged flange for extra clamping surface area.
What is it made of?
It's machined from chromoly steel with a black oxide finish.

