Precision Twist Drill 5998152 R10CO 21/32" Cobalt Jobber Length Drill Bit 135° Split Point

The Precision Twist Drill 5998152 is a heavy-duty, jobber-length drill bit from the R10CO Series, ground from M35 Cobalt High Speed Steel (HSS-Co) for superior performance in demanding drilling applications. At 21/32" (0.6563") diameter, this drill bit is engineered to tackle tough ferrous and exotic materials where standard HSS drills fall short.

Key Features:

• Drill Diameter: 21/32" (0.6563" / 16.67mm)
• Overall Length (OAL): 7-1/8"
• Flute Length: 5-3/16"
• Material: M35 Cobalt High Speed Steel (HSS-Co)
• Point Angle: 135° self-centering split point (NAS 907, Type J)
• Finish: Bronze oxide — retains lubricant for improved wear resistance and chip flow
• Shank Type: Plain round (straight shank), shank diameter matches drill diameter
• Spiral Direction: Right-hand spiral / right-hand cut
• Flute Form: Type N — regular helix angle of 21°–34°
• Specifications: ANSI, NAS 907 compliant
• Series: R10CO

The 135° split-point geometry reduces walking when starting a hole, enabling more accurate hole placement without a center punch. Suitable for drilling to a depth up to 4× the drill diameter. Originally designed for the aircraft industry, the R10CO series performs exceptionally well across a wide range of materials including hardened and tempered alloy steel, nodular graphite, malleable cast iron, titanium, and alloyed nickel.