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 M&P 9mm .40/.357 Recoil Spring 14lb. $14.97 Smith & Wesson K frame Yoke, old style with gas ring $100.00