Full Scale - 4mm Flat Curve - Tip Only. With each depression this tip outlines a 4mm wide full scale with a flat curve. It actually pushes down the wood behind the scale, leaving a clean, raised scale of uniform size. Use with the Binding-Post Interchangeable-tip Pen #BPH(327301), or they can be purchased as standard fixed-tip pens. Many of Razortip's scale tips use laser-welding technology, resulting in a more uniform, durable tip than ever before possible.