The MachinistPost Blog

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.

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.

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.

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.

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.

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.

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.

Structural bolt holes have defined sizes per AISC Table J3.3. Knowing the standard, oversized, and slotted hole dimensions — and which drill produces them — is fundamental to structural fabrication.

Blind holes don't give chips a way out, don't let coolant drain, and require active depth control. In thick plate, every one of these gets harder.

The gap in an interrupted cut is where drills break. The re-engagement impact — not the cutting itself — is the failure mode. Here is how to manage it.

H7 means reaming. H11 means careful drilling. Understanding ISO hole tolerances tells you which process your drawing actually requires.

Too much allowance and the reamer deflects. Too little and it rubs. The standard 0.010 to 0.015 inch rule is a starting point — here is how material and diameter shift the correct range.

Mill scale can hit 500 HBW on a 120 HBW steel. Understanding how scale and weld surface affect drill entry keeps your cobalt edges from wearing down before they reach base metal.

Tapping is faster. Thread milling is more flexible. Knowing when to switch saves tools, time, and broken tap extractions.

Counterbores seat socket head cap screws. Countersinks seat flat-head fasteners. Understanding the geometry difference is the first step.

Most tapping failures start before the tap touches the part. Here is how to drill the hole so the tap has a chance.

How to plan a fixture plate that makes drilling faster and more accurate — hole spacing, edge distance, workholding rules.