The Alvord Polk 625-0 straight flute bridge reamer is a Morse taper shank tool made of high-speed steel with no finish or coating, and is most commonly chosen for reaming uninterrupted cuts in structural steel. Bridge reamers are tapered to allow the reamer to enter overlapping and misaligned holes where extremely precise tolerances are not necessary.
Straight flute reamers are useful for uninterrupted cuts in general purpose applications. These reamers make small, circular, and precise enlargements to through and blind holes. High-speed steel is a general purpose steel for cutting tools and is compatible with many metalworking materials. It is often lower in price than other cutting tool materials. Taper shank tools can be self-holding or self-releasing based on the degree of taper – small tapers are self-holding within the toolholder, while large tapers are self-releasing and will easily release from the toolholder. The end of Morse taper shank tools (held in a toolholder) is tapered to ensure accurate alignment of the tool in its socket and is self-holding (friction between the tool and the tool-holder prevents slippage). Morse taper is one of the most widely used standards for self-holding tapers.
For reamers in the 625-0 series with 0.3750 to 0.9375 inches diameter there are five flutes, and for 1.0000 to 1.5000 there are six flutes. Tolerances are +0.0030/+0.0060 inches for all reamers in the 625-0 series.
Reamers are used to finish existing holes. When holes are created using common applications like drilling or punching they often have minute imperfections. Their roundness may be flawed, or their diameter may be slightly smaller than required. Reamers are made to exacting tolerances, so they can correct such errors and create precisely round holes of exacting dimensions. Reaming is often used before tapping screw threads.
Alvord Polk manufactures a broad family of cutting tools, brushes, and tooling components, following ISO 9001 standards for quality and environmental impact of their products. Their offices and manufacturing facilities have been located in the United States since 1881.