Seco 02139 Tool Bit Blank 4x4x63mm WKE45 Cobalt Square

Product Description

The SECO 02139 is a square tool bit blank machined from WKE45-grade cobalt high-speed steel. Blanks at this specification are unground stock used by toolroom machinists and grinding shops to fabricate custom single-point lathe tools, form tools, or specialty cutters. The 02139 measures 4 mm wide by 4 mm high with an overall length of 63 mm, giving the toolmaker sufficient stock to grind precise geometries to job-specific requirements. WKE45 cobalt HSS delivers elevated hot hardness and wear resistance compared to standard M2-grade HSS, making it well suited for interrupted cuts, tough alloys, and applications where tool life under heat is critical.

This tool bit blank is used in toolroom, job shop, and maintenance machining environments where ground-to-shape lathe bits, boring tools, or form tools are required. The square cross-section and consistent stock dimensions allow for predictable material removal during offhand or precision surface grinding. Typical applications include fabricating tools for manual engine lathes, turret lathes, and bench-mounted tool grinders. This size is commonly selected for light finishing, threading, and profiling work on small-bore or precision components.

Key Features

• WKE45 cobalt high-speed steel for superior hot hardness and extended tool life
• Square cross-section — 4 mm width by 4 mm height — for consistent blank geometry
• 63 mm overall length provides adequate stock for grinding and re-grinding
• Unground blank allows the toolmaker to grind custom relief, rake, and clearance angles
• Single-piece packaging with no minimum order beyond one unit

Compatibility

Designed as an unground tool bit blank for use in standard tool holders and grinder setups that accept 4 mm square shank tooling.

Installation Notes

Tool bit blanks require offhand or precision surface grinding to achieve the final cutting geometry before use in a lathe or boring application. Secure the blank firmly in an appropriate grinding fixture or tool rest to maintain consistent angles during shaping. Follow shop safety protocols when grinding HSS — use eye protection, proper wheel guards, and adequate coolant or intermittent grinding passes to prevent overheating the blank. Only qualified toolroom personnel or machinists with grinding experience should perform the shaping operation.