Drill America
Drill America 1/4" - 1/2" Cobalt Heavy Duty Jobber Length Drill Bit
Cobalt jobber drill set covers 1/4 to 1/2 inch with 135-degree split point for self-centering starts in stainless steel, Inconel and titanium
- ColorTransparent
- Cobalt steel delivers high red hardness for faster drilling
- 135° split point self-centres and reduces thrust on tough metals
- Manufactured to NAS 907 standard for aerospace-grade reliability
- Effective on stainless steel, inconel and titanium alloys
- 30% higher speeds than conventional M2 high-speed steel
1/4"–1/2" Cobalt Jobber Drill Set
This 16-piece Drill America set covers diameters from 1/4" to 1/2" in cobalt steel. Each bit meets National Aerospace Standard 907 and features a 135° split point for self-centering starts. The heavy-duty jobber length suits machine or handheld drilling in tough alloys. Cobalt construction maintains hardness at elevated temperatures.
Metalworkers drilling stainless, Inconel, titanium
Shops that need faster penetration in high-tensile alloys will benefit from the 30% speed gain over M2 high-speed steel. The 135° split point reduces thrust and walking on hard surfaces. Buyers who only drill wood, plastic or soft aluminium will not use the heat resistance this set provides. Sets requiring sizes below 1/16" or above 1/2" must look elsewhere.
135° split point geometry
The 135° split point centres without a centre punch and cuts thrust force, letting the cobalt substrate run up to 30% faster in stainless steel, Inconel and titanium. Smaller bits below 1/16" or #52 and larger bits above 1/2" revert to a 118° standard point. This single angle change determines whether the bit walks or bites in hard metal.
Highlights
- Cobalt steel delivers high red hardness for faster drilling
- 135° split point self-centres and reduces thrust on tough metals
- Manufactured to NAS 907 standard for aerospace-grade reliability
- Effective on stainless steel, inconel and titanium alloys
- 30% higher speeds than conventional M2 high-speed steel
Specifications
| Brand | DRILL AMERICA |
|---|---|
| Color | Transparent |
Questions about this item
Does the 135 split point keep the cobalt bit from walking on stainless steel during long drilling sessions?
The 135 split point is self-centering and reduces thrust, so the bit starts on target without a centre punch and cuts stainless steel with less force.
What size range does the set cover so I know which holes I can drill without buying extra bits?
The set includes jobber-length bits from 1/4 inch up to 1/2 inch, covering the common range for heavy-duty cobalt drilling.
Will the 118 standard point on the largest bits work in my older drill press without modification?
Bits larger than 1/2 inch use a 118° standard point that fits any conventional drill press chuck without adapters.
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