The range in relaxation strengths at 950 and 1000 F appears to be due mainly to the influence of initial-stress variations, as is shown by the cross plot of initial stress versus residual stress on page 58. Material 9 which had been oil quenched and tempered (also had low Si) appeared to be falling below the normalized and tempered materials with increasing time. Re-stressing for a second relaxation period raised residual stresses, particularly at 950 F.