12. Materialman. The term "materialman" when used in this chapter, means any person who furnishes material or the use of machinery, tools, or equipment, or compressed gases for welding or cutting, or fuel or lubricants for the operation of machinery or motor vehicles, either to an owner, contractor or subcontractor, for, or in the prosecution of such improvement.
The expression "furnishes material" or other similar expression wherever used in this chapter, shall be deemed to mean and include the reasonable rental value for the period of actual use of machinery, tools or equipment, and the value of compressed gases furnished for welding or cutting, and the value of fuel and lubricants consumed by machinery operating on, or by motor vehicles owned, operated or controlled by the owner, or a contractor or subcontractor while engaged exclusively in the transportation of materials to or from the improvement for the purposes thereof.