Starrett Center Head Only for 4" Combination Squares - Ideal for Wood Workers and Metal Workers - Black Wrinkle-Finished, Cast Iron Steel Center Head - C11-4

Come on, we are talking about Starrett here. They invented the combination square in 1878. You can buy a used head in any condition spray it with a penetrating oil and lightly remove the rust with a mild abrasive like scotch-brite. You may need to buy a replacement pin to hold the blade. But you can restore any head to usable condition. All Starrett heads are either drop forged or hardened so they last a lifetime. As long as Starrett continues to make their tools in Athol, Mass they will continue to be the leader in precision tools. Anyway about this particular head. It's for the 6" blade and is wrinkle finished. The nut to hold the pin is knurled so it's easier to tighten/loosen. This is the exact tool you need to find center on small diameter objects. Always keep your heads oiled so they don't oxidize(rust) and you will leave this tool to your children when your dead and gone.

The very best,I don't think you get anything else as good as this