Machine Tap M8 DIN 376 HSSE Spiral Flute 40° Extended Length for Blind Holes

Blind-hole threading in tough materials demands a tap that clears chips efficiently and withstands high cutting temperatures. This M8 machine tap with a 40° right-hand spiral flute pulls chips backward out of the hole, preventing clogging and tap breakage in stainless steel, alloy steel, and other hard-to-machine metals. The HSSE cobalt-alloyed steel retains hardness at elevated temperatures, extending tool life in demanding production runs.

Who is it for

Machinists and manufacturing shops that regularly cut threads in blind holes, especially in high-strength or work-hardening materials. It suits CNC machining centers, tapping heads, and manual machines where reliable chip evacuation and precision thread quality are critical.

Main features

• DIN 376 standard with extended length for deep reach and clearance.
• M8 × 1.25 mm metric coarse thread, tolerance class 6H.
• HSSE cobalt high-speed steel for superior heat and wear resistance.
• 40° right-hand spiral flute designed for blind holes—chips exit upward.
• Bright finish reduces friction and improves chip flow.
• Square drive 4.9 mm for secure tap holder engagement.

Specifications

• Thread size: M8
• Thread pitch: 1.25 mm
• Thread tolerance: 6H
• Standard: DIN 376
• Material: HSSE (cobalt high-speed steel)
• Flute type: Spiral flute
• Helix angle: 40° right hand
• Overall length: 125 mm
• Thread length: 22 mm
• Shank diameter: 6.2 mm
• Square drive size: 4.9 mm
• Cutting direction: Right-hand cut
• Recommended pilot hole diameter: 6.8 mm
• Application: Blind holes
• Product series: EL (extended length)

Tips

Use a high-quality tapping fluid suitable for the workpiece material. For blind holes, ensure the hole depth exceeds the required thread depth by at least the tap's chamfer length plus chip space. Drill the pilot hole to 6.8 mm for standard 75% thread engagement. Reduce cutting speed by 30–50% compared to HSS taps when machining hardened or tough alloys.