Some of the most common types of reamers are line reamers, manual hand reamers, taper reamers, taper broaches, machine reamers and hand hones. Each type of reamer has specific applications.
Reamers are traditionally used for producing accurate and smooth surfaces in a bore. They are also used to make sure pins or bolts will have a good fit. Most metals can be machined with a reamer. Taper reamers are typically used for finishing taper bores in small pulleys and sprockets used in motorcycles. Taper broaches utilize scraping action instead of cutting action. These reamers are used for opening drilled holes to handle taper pins.
Hand reamers feature left-hand or straight spiraled flutes which help prevent the reamer from self-advancing into the bore. They are often slightly tapered to ease entrance. Line reamers feature a couple sets of cutting edges to ensure for an accurate alignment of bores. Machine reamers have normal cutting blades and can be adjusted to regulate size.
Holes that are to be reamed need to be undersized in order for the reamer to function properly. Leaving too little material before employing a reamer can cause the reamer to chatter, resulting in a wavy surface. For proper reaming, rotation needs to be slow and there must be considerable power behind the reamer. While operating a reamer, direction must stay constant; a reamer should never be operated backwards.
If lubricant is needed, oil is an acceptable material to use in most cases. Oil is an acceptable lubricant for machining steel, brass, phosphor-bronze and gunmetal. Paraffin can be employed as a lubricant for work involving duralumin and aluminum. Equal parts of tallow and graphite are acceptable lubricants that can be applied to cast-iron projects.
Reamers can be much better tools than drills in many instances and are capable of producing better finishes on materials than a lathe. Often reamers are used to finish surfaces bored by a lathe. Hand hones can be used to sharpen slightly dulled reamers by rubbing them along the flutes and relief edges.