  We investigate connections between radial Fourier multipliers on $R^d$ and
certain conical Fourier multipliers on $R^{d+1}$. As an application we obtain a
new weak type endpoint bound for the Bochner-Riesz multipliers associated to
the light cone in $R^{d+1}$, where $d\ge 4$, and results on characterizations
of $L^p\to L^{p,\nu}$ inequalities for convolutions with radial kernels.
