Context : Convective core overshooting extends the main-sequence lifetime of a star .
Evolutionary tracks computed with overshooting are quite different from those that use the classical Schwarzschild criterion , which leads to rather different predictions for the stellar properties .
Attempts over the last two decades to calibrate the degree of overshooting with stellar mass using detached double-lined eclipsing binaries have been largely inconclusive , mainly due to a lack of suitable observational data .

Aims : Here we revisit the question of a possible mass dependence of overshooting with a more complete sample of binaries , and examine any additional relation there might be with evolutionary state or metal abundance Z .

Methods : We use a carefully selected sample of 33 double-lined eclipsing binaries strategically positioned in the H-R diagram , with accurate absolute dimensions and component masses ranging from 1.2 to 4.4 M _ { \sun } .
We compare their measured properties with stellar evolution calculations to infer semi-empirical values of the overshooting parameter \alpha _ { ov } for each star .
Our models use the common prescription for the overshoot distance d _ { ov } = { \alpha _ { ov } } H _ { p } , where H _ { p } is the pressure scale height at the edge of the convective core as given by the Schwarzschild criterion , and \alpha _ { ov } is a free parameter .

Results : We find a relation between \alpha _ { ov } and mass that is defined much more clearly than in previous work , and indicates a significant rise up to about 2 ~ { } M _ { \sun } followed by little or no change beyond this mass .
No appreciable dependence is seen with evolutionary state at a given mass , or with metallicity at a given mass despite the fact that the stars in our sample span a range of a factor of ten in [ Fe/H ] , from -1.01 to +0.01 .

Conclusions :