Cle-line C23357 Jobber Drill Bit Letter E 1/4 in Cobalt

Product Description

The CLE-LINE C23357 is a cobalt jobber length drill bit sized at Letter E (0.2500 inches / 1/4 inch), built for high-performance drilling in tough materials. The 135-degree split point reduces walking and requires no center punch on most surfaces. With a gold finish, web-thinned geometry, and a tapered web configuration, this bit is engineered for heavy-duty production drilling. The overall length is 4 inches, with a 2.75-inch flute length and a straight-cylindrical shank of 0.2500 inches. Two spiral flutes channel chips efficiently and help maintain cutting speed under load. This bit conforms to ASME B94.11M and is rated for continuous shop use.

The C23357 is designed for right-hand cutting applications across a range of workpiece materials including aluminum, titanium, and superalloys. It fits standard jobber-length drill chucks and is suited for use in manual drill presses, CNC drilling centers, and hand-held power tools where a 1/4-inch straight-shank bit is required. The cobalt construction allows it to handle elevated cutting temperatures without losing hardness, making it a practical choice for aerospace-grade materials and stainless alloys encountered in mechanical and fabrication work.

Key Features

• Cobalt construction with gold finish for heat resistance and extended tool life in hard materials
• 135-degree split point reduces thrust and eliminates the need for center punching
• Web-thinned, tapered web design improves chip evacuation and reduces cutting resistance
• Right-hand spiral flutes (quantity: 2) provide efficient chip clearing during through-hole drilling
• Straight-cylindrical shank (0.2500 inches) fits standard 3-jaw chucks without adapters
• Meets ASME B94.11M standard; diameter tolerance held to +0.0000 / -0.0007 inches

Compatibility

Designed as an OEM-style heavy-duty replacement or direct-use jobber drill bit for applications requiring a 1/4-inch (Letter E) straight-shank cobalt bit rated for aluminum, superalloy, and titanium workpiece materials per CLE-LINE Series 1802.

Installation Notes

Machinists and fabricators should secure the shank fully in the chuck and verify runout before beginning a drilling cycle. Always power down or lock out the machine before changing bits. When drilling titanium or superalloys, use appropriate cutting fluid to manage heat buildup and extend bit life. Follow applicable shop safety standards and machine manufacturer guidelines for speed and feed settings.