Value Collection 557u 4 Taper Pin Reamer Size 4 Hss

Product Description

The VALUE COLLECTION 557u 4 is a Size 4 taper pin reamer designed for hole enlarging, hole finishing, and hole shaping operations in precision machining and tool-and-die work. Constructed from high speed steel (HSS) with a bright/uncoated finish, this reamer features a left-hand spiral flute with right-hand cutting action, which helps pull chips away from the cutting zone during use. The small end diameter is 0.2071 inches and the large end diameter is 0.2604 inches, with a taper rate of 1:48. Overall length is 4.0625 inches with a flute length of 2.5625 inches. A square shank with a diameter of 0.2656 inches provides positive drive in a standard tap wrench or machine holder.

This reamer is suited for general-purpose use in job shops, toolrooms, and maintenance environments where taper pin holes must be sized or finished to accept standard Size 4 taper pins. Typical applications include fitting taper pins in shaft collars, gears, and mechanical assemblies where precise alignment and secure retention are required. The 1:48 taper conforms to the standard taper pin series, making it appropriate for both new hole preparation and rework of existing taper pin bores.

Key Features

• Size 4 taper pin geometry with a 1:48 taper rate for standard taper pin fitment
• High speed steel construction provides durability across a range of workpiece materials
• Left-hand spiral flute with right-hand cut promotes chip evacuation and smooth finish
• Bright/uncoated finish suitable for general-purpose machining applications
• Square shank (0.2656 inches diameter) for positive drive in tap wrenches and machine spindles
• 4.0625-inch overall length with 2.5625-inch flute length for adequate reach in typical assemblies

Compatibility

Designed as a general-purpose replacement and standard-use reamer for Size 4 taper pin applications conforming to the 1:48 taper pin series.

Installation Notes

Taper pin reamers are typically operated by machinists or maintenance technicians using a tap wrench for hand reaming or a drill press and milling machine for machine reaming. Secure the workpiece fully before reaming and apply cutting fluid appropriate for the workpiece material to extend tool life and improve surface finish. Advance the reamer gradually, clearing chips frequently, and avoid applying side pressure that could cause taper misalignment. Always verify fit with the actual taper pin before final assembly.