Gun drilling produces deep, straight holes (up to 100× diameter) using high-pressure coolant through the tool. Correct coolant pressure and feed are critical -- too little...
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Request a Proposal →Gun drilling produces deep, straight holes (up to 100× diameter) using high-pressure coolant through the tool. Correct coolant pressure and feed are critical -- too little pressure and chips pack; too much feed and the drill wanders.
Gun drilling is economical for holes deeper than 10× diameter. For 5-10×D, parabolic-flute carbide drills often perform better with simpler setup. Below 5×D, standard carbide drills are faster and cheaper. The sweet spot for gun drilling is 15-50×D.
Very. Gun drill coolant passages are small (0.5-2 mm) and easily clogged. Use 10-micron or finer filtration. A single chip or contaminant can block the coolant hole and destroy the drill instantly. Many shops dedicate a separate filtration system to their gun drill machine.
Uneven material hardness, incorrect starting bushing alignment, excessive feed, insufficient coolant pressure, and dull drills all cause wandering. The starting bushing must guide the drill within 0.005 mm alignment. A pilot hole helps; pecking at the start helps the drill find its centre.
Enter the drill diameter and hole depth. The calculator recommends coolant pressure, feed per revolution, and spindle RPM. These are starting values -- adjust based on material, coolant type, and machine capability.
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Use the calculator freely. If the result points to a tooling or process problem, we can source the exact carbide tooling you need from vetted factories in China. Compare factory-direct pricing.
Before you commit to a spec, it helps to know what the market pays for it. These are real, publicly listed factory prices — not a quotation, and not a guess.
We source the tool families below direct from vetted Chinese factories, matched to the material and tolerance you just worked out. Every batch ships with its material certificate and dimensional record.
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DEEP-HOLE DRILLING? Gun drilling depends on the coolant channels as much as on the geometry, and those are not visible on a catalogue page. See what we check on a deep-hole tool before shipping.
Below about 20×D the tool, the coolant pressure and the guide bush all have to agree, or the hole drifts. Send the depth, diameter and material.