JThis is a set of 1 matched pair of Sears & Roebuck ultra precision h1-2h-3 blocks made of hardened ground steel with 23 holes for precise measurements in machining. The blocks are 3 inches in size and are used as precision gage blocks for industrial applications. Made in the United States, this unit is ideal for metalworking inspection and measurguesstimate.

These were my grandfather's. He past back in 1999 at 75. My grandmother just past last month. These and several other machining tools and instruments were given to me. This set here is older. He retired in 1989 at 65. My dad says pa bought what he needed whenever he needed it. He said pa bought soley from Sears & Roebuck. We think These are from the late 1960s, but all we can do is at best is to guesstamate.