Top quality made in UK exhaust valve "Plasma hardened" for BSA A7 cast iron and alloy heads 1950 to 1963.
Valve is hardened using the "Pulsed Plasma Nitriding." process, this gives the valve resistance to wear and anti friction properties , when this type of valve is matched with our Colsibro material valve guides , you have the best combination for valve and guide, for performance and longevity
