Jobber Length Drill Bits: The General-Purpose Choice

A jobber-length drill bit is a common, general-purpose-length twist drill. “Jobber” describes the bit’s length family—not its diameter, cutting material, point angle, coating or intended workpiece. It is the practical default when a stub bit is too short and an extra-length bit is unnecessary.

That distinction matters when buying. A listing that says only “jobber length” does not tell you whether the bit is HSS, cobalt-alloyed HSS or carbide; whether it has a 118° or 135° point; or whether its shank fits your chuck. Manufacturers list these as separate attributes. For example, Guhring identifies its Series 651 separately as jobber length, HSS, 118°, right-hand cutting and straight-shank (Guhring Series 651).

How long is a jobber drill bit?

There is no single overall length for all jobber bits. Flute length and overall length increase in steps with diameter. One published inch series gives these dimensions:

Bit diameter	Flute length	Overall length
1/8 in.	1-5/8 in.	2-3/4 in.
1/4 in.	2-3/4 in.	4 in.
5/16 in.	3-3/16 in.	4-1/2 in.
3/8 in.	3-5/8 in.	5 in.
1/2 in.	4-1/2 in.	6 in.

These are nominal dimensions from a jobber drill size chart, not a guarantee for every product. Metric series may follow different dimensions. Greenfield’s published table, for example, lists a 6 mm jobber drill with 57 mm of flute length and a 93 mm overall length; its 10 mm drill has an 87 mm flute length and 133 mm overall length (Greenfield standard drill dimensions).

Check the manufacturer’s actual flute length and overall length whenever reach or machine clearance is close. “Jobber” is broader than one dimensional standard and does not automatically promise DIN 338 dimensions (Slugger Tool’s jobber specification guide).

Flute length also is not unrestricted drilling depth. Allow for the point, keep the chuck clear of the work and leave enough flute outside the hole for chips to escape. Deeper holes may require periodic withdrawal to clear chips.

Jobber vs. stub and extra-length drills

Choose the shortest bit that provides the necessary working reach:

• Stub or screw-machine length: Better for shallow holes when rigidity matters most. The shorter projection leaves less opportunity for the bit to flex or wander.
• Jobber length: The middle-length choice for routine drilling, including many through-holes and moderate-depth blind holes.
• Long-series or extra-length: Use when access or hole depth demands it. Extra reach increases deflection risk and makes chip evacuation more difficult.

These are length families rather than performance grades; shorter formats prioritize rigidity, while longer formats prioritize reach (Slugger Tool). Do not buy extra length as insurance. If a stub drill reaches the full hole depth, its greater rigidity is usually useful. If a jobber drill reaches, an extra-length drill adds drawbacks without improving the cutting material or geometry.

Choose the cutting material separately

Length does not determine what the drill can cut.

Standard HSS is a sensible starting point for wood, plastics and many ordinary metals when the complete drill is rated for the workpiece. It is relatively tough and well suited to general handheld drilling. For a fuller material comparison, see our guide to choosing HSS.

Cobalt-alloyed HSS retains hardness at higher cutting temperatures and is commonly offered for difficult metals. Norseman’s M42 jobber line contains 8% cobalt and calls for rigidly held, positive-feed equipment (Norseman M42 jobber drills). That is a useful warning: a premium alloy cannot compensate for a loose workpiece, excessive speed or an unstable setup. For stainless specifically, use the process in our stainless-steel drilling guide.

Carbide offers high wear resistance but is less forgiving of runout, vibration and interrupted handheld feed. Do not choose solid carbide merely because it sounds like an upgrade; machine rigidity and the intended material matter. Compare the trade-offs in our tungsten carbide drill-bit guide.

Check the point, shank and size

Before ordering a bit or set, verify:

1. Exact diameter: Fractional, letter, number and metric systems overlap imperfectly. For a tapped hole, use the drill specified for the exact thread and tap type rather than the nearest familiar fraction.
2. Point geometry: Jobber drills are available with multiple points. Guhring’s cited series uses 118°, while Norseman offers 135° split-point jobber drills (Norseman jobber drills). A split point can improve starting, but workpiece material and the manufacturer’s application range still control the choice.
3. Shank diameter and form: Confirm that the chuck opens far enough and can grip the shank securely. A reduced-shank bit lets a smaller chuck hold a larger cutting diameter, but it does not increase the drill’s torque capacity.
4. Flute and overall length: Check both hole reach and clearance behind the drill. Base usable reach on the intended chucking position, not simply the bit’s total length.
5. Material rating: Match the complete bit specification to the workpiece. A metal-cutting jobber twist drill is not a substitute for a masonry, tile or purpose-built wood bit; see the broader drill-bit type guide.

Practical operating limits

Wear eye protection, clamp the workpiece, and grip the shank securely without clamping on the flutes. Keep the drill aligned with the intended hole. Use speed and feed guidance for the exact bit diameter and workpiece rather than one setting for an entire set.

Watch chip flow. The flutes provide the route out of the hole, and flute and helix geometry affect chip evacuation (Harvey Performance’s drill-geometry guide). If chips pack into a deeper hole, stop feeding and clear them; forcing the drill raises heat and can jam or break it.

For most drill owners, a sound jobber set is the versatile baseline. Buy a stub drill for a specific shallow operation and a longer drill only when measured reach requires it. “Jobber” settles the length category; diameter, usable reach, cutting material, point, shank and workpiece determine whether the drill is actually right.