High Performance Valves

 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.

STK Performance Valves are forged using 21-4N Stainless Steel which is much stronger and suitable for most applications.

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.


214N is considered to be the premium material for Performance Valves.

Most of our Stainless Steel Valves are produced with an 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.

STK Performance Valve Sets are complimented with the fitment of the STK Competition Valve Spring Kit ( REV KiT )