Sutton 1mm Left Hand Cobalt Jobber Drill Bit - Cobalt
Available
The Sutton D202 Left Hand Cobalt is a jobber drill in cobalt high speed steel (HSS-Co) with a colour-temp finish. It has 30° left-hand helix flutes (L30), a 118° standard point, and is made to DIN 338.
Left-hand helix for screw machine applications where spindles rotate counter-clockwise; cobalt content for high abrasion and heat resistance; shorter drilling length designed for rigidity.
This is the metric range: 15 sizes from 1 to 13 mm, with flute lengths of 12 to 101 mm and overall lengths of 34 to 151 mm. Every size in this range is supplied in packs of 1.
Where this product is used
- Screw machine and other applications where the spindle rotates counter-clockwise, which is the purpose of the left-hand cobalt jobber.
- Machine drilling on a drill press, mill or lathe and, where the drill's catalogue entry allows it, hand-held drilling.
- Materials rated Optimal for this drill: non-alloy steel, about 0.15 %C, annealed; non-alloy steel, about 0.45 %C, annealed; low-alloy steel (under 5% alloying elements), annealed; and wrought aluminium and magnesium alloys.
- Also rated Effective: non-alloy steel, about 0.45 %C, quenched and tempered (250 HB); non-alloy steel, about 0.75 %C (annealed and quenched and tempered); low-alloy steel, quenched and tempered (275 to 350 HB); high-alloy and tool steel; grey cast iron; nodular cast iron; cast aluminium and magnesium alloys (up to 12% Si); cast aluminium alloys over 12% Si; free-cutting copper alloys; brass; bronze; thermosetting and fibre-reinforced plastics; and chilled cast iron.
- Hole depths to 5 × Ø. Step feeding or pecking is required beyond 3 × Ø.
Finish
Colour temp.
Cutting speeds and feeds
Cutting speeds (Vc) and feed numbers for this drill are from the Sutton Application Guide. The table lists the material groups covered, with the speed and the rpm and feed it works out to at Ø6 mm and Ø10 mm. Speed (rpm) = Vc × 1000 ÷ (π × Ø). Treat these as starting values and adjust for the machine, set-up and coolant.
| Material (VDI 3323 group) | Rating | Vc (m/min) | Feed no. | Ø6 mm: rpm / feed | Ø10 mm: rpm / feed |
|---|---|---|---|---|---|
| Non-alloy steel, about 0.15 %C, annealed | Optimal | 12 | 5 | 635 rpm / 0.125 mm/rev | 380 rpm / 0.19 mm/rev |
| Non-alloy steel, about 0.45 %C, annealed | Optimal | 10 | 5 | 530 rpm / 0.125 mm/rev | 320 rpm / 0.19 mm/rev |
| Non-alloy steel, about 0.45 %C, quenched and tempered | Effective | 8 | 5 | 425 rpm / 0.125 mm/rev | 255 rpm / 0.19 mm/rev |
| Non-alloy steel, about 0.75 %C, annealed | Effective | 8 | 5 | 425 rpm / 0.125 mm/rev | 255 rpm / 0.19 mm/rev |
| Low-alloy steel (under 5% alloying), annealed | Optimal | 8 | 5 | 425 rpm / 0.125 mm/rev | 255 rpm / 0.19 mm/rev |
| Low-alloy steel, quenched and tempered (275 HB) | Effective | 8 | 4 | 425 rpm / 0.1 mm/rev | 255 rpm / 0.16 mm/rev |
| High-alloy and tool steel, annealed | Effective | 8 | 5 | 425 rpm / 0.125 mm/rev | 255 rpm / 0.19 mm/rev |
| Grey cast iron, ferritic / pearlitic | Effective | 12 | 6 | 635 rpm / 0.16 mm/rev | 380 rpm / 0.24 mm/rev |
| Nodular cast iron, ferritic | Effective | 12 | 6 | 635 rpm / 0.16 mm/rev | 380 rpm / 0.24 mm/rev |
| Wrought aluminium and magnesium, non heat treatable | Optimal | 25 | 5 | 1,330 rpm / 0.125 mm/rev | 795 rpm / 0.19 mm/rev |
| Wrought aluminium and magnesium, heat treatable | Optimal | 25 | 5 | 1,330 rpm / 0.125 mm/rev | 795 rpm / 0.19 mm/rev |
| Cast aluminium and magnesium (up to 12% Si), non heat treatable | Effective | 18 | 4 | 955 rpm / 0.1 mm/rev | 575 rpm / 0.16 mm/rev |
| Cast aluminium over 12% Si | Effective | 12 | 6 | 635 rpm / 0.16 mm/rev | 380 rpm / 0.24 mm/rev |
| Copper alloys, free cutting (Pb > 1%) | Effective | 20 | 4 | 1,060 rpm / 0.1 mm/rev | 635 rpm / 0.16 mm/rev |
| Brass (CuZn, CuSnZn) | Effective | 15 | 4 | 795 rpm / 0.1 mm/rev | 475 rpm / 0.16 mm/rev |
| Bronze (CuSn) | Effective | 15 | 4 | 795 rpm / 0.1 mm/rev | 475 rpm / 0.16 mm/rev |
| Thermosetting and fibre-reinforced plastics | Effective | 25 | 3 | 1,330 rpm / 0.08 mm/rev | 795 rpm / 0.125 mm/rev |
| Chilled cast iron | Effective | 10 | 5 | 530 rpm / 0.125 mm/rev | 320 rpm / 0.19 mm/rev |
Feed rates (mm/rev) for the feed numbers above:
| Ø (mm) | Feed no. 3 (mm/rev) | Feed no. 4 (mm/rev) | Feed no. 5 (mm/rev) | Feed no. 6 (mm/rev) |
|---|---|---|---|---|
| 2 | 0.03 | 0.04 | 0.05 | 0.06 |
| 3 | 0.045 | 0.055 | 0.07 | 0.09 |
| 4 | 0.06 | 0.075 | 0.09 | 0.12 |
| 5 | 0.07 | 0.09 | 0.11 | 0.14 |
| 6 | 0.08 | 0.1 | 0.12 | 0.16 |
| 8 | 0.1 | 0.13 | 0.16 | 0.2 |
| 10 | 0.12 | 0.16 | 0.19 | 0.24 |
| 12 | 0.15 | 0.18 | 0.23 | 0.28 |
| 16 | 0.19 | 0.23 | 0.29 | 0.36 |
| 20 | 0.23 | 0.28 | 0.34 | 0.42 |
| 25 | 0.27 | 0.33 | 0.41 | 0.5 |
| 32 | 0.33 | 0.41 | 0.5 | 0.6 |
| 38 | 0.38 | 0.46 | 0.56 | 0.68 |
| 45 | 0.43 | 0.52 | 0.64 | 0.76 |
| 52 | 0.48 | 0.58 | 0.7 | 0.84 |
| 63 | 0.56 | 0.67 | 0.8 | 0.96 |
Drilling notes
- Step feeding or pecking is required for holes deeper than 3 × Ø.
- When drilling a cast or black (not machined) surface, reduce the drilling speed by 20%.
- For optimal positional accuracy and hole size, spot the hole first with a Sutton spotting drill (D175).
- For hole depths greater than 7 × Ø, pre-drill a pilot hole first for accurate hole position and to stop the drill wandering. The pilot can be drilled with a short, rigid drill, about 3 × Ø deep, at reduced feed.
Deep holes: reduce speed and feed as hole depth increases.
| Hole depth | Reduce speed by | Reduce feed by |
|---|---|---|
| 3 x diameter | 10% | 10% |
| 4 x diameter | 30% | 10% |
| 5 x diameter | 30% | 20% |
| 6 to 8 x diameter | 35 to 40% | 20% |
Accuracy
Sutton drills are ground to an h8 diameter tolerance (the diameter may be at nominal or smaller, never larger) with a small back taper behind the point.
| Drill diameter (mm) | h8 tolerance (minus only) | Back taper per 10 mm flute length |
|---|---|---|
| 0.2 to 3 | 14 µm | 0 to 0.008 mm |
| 3 to 6 | 18 µm | 0.002 to 0.008 mm |
| 6 to 10 | 22 µm | 0.002 to 0.009 mm |
| 10 to 18 | 27 µm | 0.003 to 0.011 mm |
| 18 to 30 | 33 µm | 0.004 to 0.015 mm |
| 30 to 50 | 39 µm | 0.004 to 0.015 mm |
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
| Specification | Detail |
|---|---|
| Catalogue code | D202 |
| Range name | Left Hand Cobalt |
| Type | Jobber series |
| Material | High Speed Steel Cobalt (HSS Co) |
| Finish | Colour temp |
| Flute geometry | 30° left-hand helix (L30) |
| Point | 118° standard point |
| Standard | DIN 338 |
| Diameter tolerance | h8 |
| Designation | N |
| Drilling depth | up to 5 × Ø |
| Sizes in this range | 15 sizes, 1-13mm |
Related drilling products
Compare other Sutton drills: D109 heavy-duty cobalt, D180 R40 Inox and D101 Silver Bullet. Sets are in the Metric Jobber Drill Sets and the Imperial Jobber Drill Sets. 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. The cobalt drill bit guide explains cobalt grades.
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