Check the listing for details. Blacksmith Scribe, Knife Maker's Center Line Scribe, 2 x 72 Knife Maker Scribe. Condition: New. Listed at 26.99 USD. This New Knife Center Line Scribe is one Blacksmith's will love. This scribe uses 2 high quality, abec 3, deep groove radial ball bearings. The body is made of 1/2" X 1/2" square 1018 steel stock and is approximately 4" long. The spacing between the bearings is approximately 2-11/16" inches and they are equally spaced from the carbide point. This will scribe the center of flat bar stock up to 2-5/8" wide. You rotate the scribe on the work until the bearings touch on each side of the stock. Just keep the work in contact with the bearings and drag the tool. This is a simple self centering design that will find the center of the stock by the rotation of the tool. The tungsten carbide rod is approximately 1-1/2" long X approximately 1/8" diameter. One end has a slight chamfer and the other end has been professionally ground to a sharp 60 degree point. Please Note: Ruler is NOT included.