The MachinistPost Blog

An annealed HSS drill looks almost the same as a good one. It cuts soft for a few holes, then fails. Here is how to identify heat damage in the field and what causes it in the first place.

On a manual drill press, the feed rate is in your hands — literally. Learning to read what the drill is telling you through the quill handle is one of the most underrated skills in manual machining.

Carbide drills are more brittle than HSS. Runout that an HSS drill handles without complaint will crack a carbide drill at the cutting edge. Here are the TIR specs to hold and how to verify them before you cut.

Drilling into round stock without proper support is how you get parts that spin, fingers that get cut, and holes that wander. V-blocks and magnetic bases are the two workholding tools that fix all three.

Running coolant at the wrong concentration is one of the most common — and easiest to fix — causes of short drill life. How to mix it correctly, measure it in the field, and know when to dump and start fresh.

A new drill bit that skips break-in can chip an edge on the first hole and never recover. Here is the break-in procedure most machinists skip — and why it extends tool life by 20-40%.

When you need an angled hole, you have two options: tilt the table or tilt the workpiece. Both work. Neither is foolproof. Here is how to choose and execute each method correctly.

A drill press table that is not square to the spindle produces angled holes and ruins close-tolerance reaming. How to check and correct tram in under 20 minutes using a dial test indicator.

Carbide is harder but brittle. Cobalt bends without shattering. In interrupted drilling — keyways, stack plates, castings with voids — toughness beats hardness. The complete comparison with speed and feed adjustments.

When the drill press cannot reach the hole location, extensions and angle heads get you there. Understanding runout amplification, feed adjustments, and when extensions are the wrong answer entirely.

Mag drills go where drill presses cannot. Surface prep, annular cutter selection, coolant delivery, and safety restraints — the complete guide to running a magnetic drill press correctly in structural steel.

For large-diameter holes, the choice between a holesaw, a large twist drill, a step drill, and an annular cutter determines cycle time, finish, and whether you hit tolerance. Here is the decision framework.

The drill that works great on a Haas may eat itself on a Bridgeport. Point geometry, coating, flute profile, and length all change between CNC and manual setups. Here is the breakdown by machine type.

Reaming only works if the drilled hole going in is right. Here is what machinists need to know about drill-to-ream prep — allowance, point geometry, and the checks to do before the reamer touches the work.

Belt drill presses have 5 to 12 speed settings and no continuous adjustment. Choosing the right one for each drill size and material is a skill that pays off directly in drill life and hole quality.

Runout enlarges holes and breaks small drills. The fix is different depending on whether the problem is in the chuck, the spindle, or the drill itself. Here is how to isolate which one is causing it.

Chips are your best diagnostic tool. Long stringy chips, blue chips, powdery dust — each tells you something different about speed, feed, tool condition, and material. Here is how to read them and what to change.

Most drilling injuries and scrapped parts trace to inadequate workholding. The breakthrough torque spike that spins unsecured parts is larger than people expect. Here is what actually holds work for drilling.

Gang drilling multiplies output on repetitive hole patterns without adding machines. Table stop systems, per-station speed settings, and drill life monitoring are the three variables that determine whether it works.

The depth stop is what makes consistent blind holes possible at production rates. Setting it correctly requires accounting for drill tip geometry — most operators skip this step and wonder why depth varies.

Holes deeper than 4× diameter need a different approach. Peck increment sizing, coolant delivery method, and tool geometry all shift when depth goes up. Here is the correct setup for each variable.

Standard helix flutes work fine to 3–4× diameter. Past that, chip packing is the failure mode. Parabolic flute geometry solves this — if your L/D ratio calls for it.

Center drills belong in lathes. Spot drills belong in machining centers. The 60° vs 118° angle mismatch is why using a center drill as a spot drill causes drill walk — not user error, geometry conflict.

Stainless steel work-hardens instantly when the drill rubs instead of cuts. Cobalt grade, correct SFM (25–40), and aggressive feed are the three variables that determine whether you get a clean hole or a burned edge.