Sutton 2mm Black Magic Jobber Drill Bit - Metric - Cobalt

The Sutton D169 Black Magic is a jobber drill in 5% cobalt high speed steel (HSS-Co) with a TiAlN coating. It has 40° right-hand helix flutes (R40), a 4 facet Form C point (130° on sizes up to 4.0 mm, 120° above; Form A on the largest sizes) and an endmill shank, d2 to h7. It is made to DIN 338.

High performance drill; excellent solution for austenitic stainless steels and most long chipping materials; optimised geometry ensures no work hardening and high productivity; endmill shank for greater accuracy; TiAlN for longer tool life.

This is the metric range: 142 sizes from 2 to 20 mm, with flute lengths of 24 to 140 mm and overall lengths of 49 to 205 mm. Working to a different size system? The same drill is also listed as the imperial range.

Where this product is used

• Austenitic stainless steels and most long-chipping materials, the main targets of this drill (optimised geometry so the material does not work harden).
• Materials rated Optimal for this drill: austenitic stainless steel; duplex stainless steel; and precipitation-hardening stainless steel.
• Also rated Effective: low-alloy steels; wrought aluminium and magnesium alloys; cast aluminium and magnesium alloys (up to 12% Si); copper alloys, brass and bronze; and titanium and titanium alloys.
• Rated Optimal for some grades and Effective for others: non-alloy steels; and ferritic and martensitic stainless steels.
• Hole depths to 5 × Ø. Step feeding or pecking is required beyond 3 × Ø.

Finish

Titanium aluminium nitride (TiAlN). TiAlN has a microhardness of 3300 HV and thermal stability up to about 900 °C (1652 °F), and is used for abrasive and difficult-to-machine materials such as stainless steel, higher speeds and feeds, and reduced or no coolant.

Cutting speeds and feeds

Cutting speeds (Vc) and feed numbers for this drill are from the Sutton High Performance catalogue application guide. The table lists the material groups covered. Optimal ratings are shown in bold and Effective ratings in regular type. The rpm and feed columns show what the speed and feed number work out to at Ø6 mm and Ø10 mm (speed in rpm = Vc × 1000 ÷ (π × Ø)). Treat these as starting values and adjust for the machine, set-up and coolant.

Feed rates (mm/rev) for the feed numbers above:

Drilling notes

• Step feeding or pecking is required for drilling greater than 3 x Ø.
• When drilling a cast or black (not machined) surface, reduce the drilling speed by 20%.
• For optimal positional accuracy and hole size, the use of spot drills is recommended prior to drilling the desired hole; see Sutton's spotting drill range (D175).
• For hole depths greater than 7 x Ø, pre-drill a pilot hole first for more accurate hole position and to stop the drill wandering. The pilot can be drilled with a short, rigid drill about 3 x Ø deep at reduced feed.

Accuracy

The drill diameter (d1) tolerance is h8 and the shank tolerance is h7. An h8 drill diameter may be at nominal or smaller, never larger.

Troubleshooting

• Drill breaks. Dull point: sharpen; Drill has front taper due to wearing: sharpen; Insufficient lip clearance on point: grind correctly; Lip clearance too great: regrind to correct clearance angle.
• Outer corner breaks down. Flutes clogged with chips: remove drill from hole and clear the flutes; Cutting speed too high: reduce speed; Dry cutting, no lubricant at cutting edges: apply cutting fluid.
• Cutting edges chip. Lip clearance too great: regrind to correct clearance angle; Feed too heavy: reduce feed.
• Hole rough. Dull point: sharpen; Feed too heavy: reduce feed; Dry cutting, no lubricant at cutting edges: apply cutting fluid; Fixture/clamping not rigid: secure job firmly.
• Hole oversize. Unequal angle or uneven length of cutting edges: regrind to same lip lengths and angles; Spindle run-out / loose spindle: check machine.

Key specifications

Related drilling products

Compare other Sutton drills: D169 Black Magic (imperial), D168 R40 UNI, D163 DHJ and D182 R40 UNI-IK. Browse all Cobalt Drill Bits. Need help choosing? Our guide to choosing the right drill bit and drill bit selection guide cover drill types and materials, and the speeds and feeds chart and cutting tool troubleshooting guide cover speeds and common problems.