What is 21-4N?

The STK Performance Valve is forged using 21-4N Stainless Steel which is strong and can handle most applications.

What is 21-4N ?

21-4N Super alloys or high performance alloys have an ability to function at temperatures above 540ºC(1000ºF) with deformation resistance and high surface stability.

Super alloy 21-4N valve steel is widely used in the manufacture of automotive High Performance Valves.

Most production valves are made from two components to make up the valve , the valve head and the valve stem and are joint bonded by electric-resistance-heat-aided friction welding. Usually the two components are made from two different types of material / Steel.

21-4N is usually considered to be the premium material for performance exhaust valves.

Most of our Stainless Steel valves  we produce with extra overall length. This is to aid with under-bucket shimming and eliminates the use of a shim between the valve and Bucket/lifter.

The Valve is Undercut and reshaped around the head area for optimum flow and reliability.

This is best used with high rev valve spring applications to avoid valve failure , standard valve heads may break at the joint due to additional force of valve closure caused by the additional poundage of a Competition valve spring.