An electrical connector includes an insulative housing defining a mating slot, a number of contacts and a pair of metal hold downs fastened in the insulative housing. Each contact includes a contacting portion extending into the mating slot. Each metal hold down includes a first portion, a second portion perpendicular to the first portion and a connecting portion connecting the first portion and the second portion. The first portion defines a first hole, the second portion defines a second hole for maintaining solders, and the connecting portion defines a third hole connecting the first hole and the second hole. The first portion and the connecting portion are insert molded in the insulative housing with material of the insulative housing filling in the first and the third holes.