Smith & Wesson N frame hammer block, blue $20.00 Part 78 on the exploded diagram. Used, excellent condition hammer block from a Model 57, N frame revolver. Will fit other models of N frame revolvers. In stock Smith & Wesson N frame hammer block, blue quantity Add to cart Category: Smith & Wesson Related products Smith & Wesson K frame center pin spring $5.00 Smith & Wesson J Frame Rimfire Shooters Pack $19.97