The 0.3990 CHK Reamer ST FL SS HS by Field Tool Supply is designed for precision reaming in stainless steel applications. This high-speed steel (HSS) tool features a straight flute design, which enhances chip removal and provides a smooth finish. With a diameter of 0.3990 inches, it is suitable for various industrial tasks. Constructed from durable stainless steel, this reamer ensures longevity and resistance to wear. It meets industry standards for quality and performance, making it ideal for professional use in machining and fabrication.