Abstract: A heat treatment is described for producing a desired microstructure in Hastelloy Alloy X components which have small diameter, closely spaced, laser pierced holes therein. The heat treatment produces a small grain size and discontinuous carbide morphology in the component prior to the hole piercing operation, which reduces the propensity for cracking which has been found to be associated with the hole piercing operation. After the piercing operation, the component is heat treated again to increase the grain size and produce a microstructure which provides the optimum balance of creep strength and fatigue strength.