First thing you want to do is drill a pilot hole in the right location.

第一件事，你想要做的就是钻一个先导孔在正确的位置。

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Set up a slant water hole at reamer, and connect the reamer and pilot with reducing synergy flute, which strengthen the cooling and washing function and ensure the bit's effects.

在扩眼体设一斜水眼，在导眼体与扩眼体之间连接一缩径增效排屑环，强化了冷却清洗作用，从而保证钻头有较好的使用效果。

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This avoids any gradual lateral enlargement of the pilot hole.

上述技巧可以避免导航孔逐渐向外侧扩大。

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The drill would use that hole as a pilot and widen the diameter to about 28 inches, which officials have said is wide enough for the miners to be hoisted through.

CNN: Drilling to reach Chile miners yet to begin

After the word leaked, "we started to celebrate somewhat, " enjoying good times at a local test pilot watering hole.

CNN: Where planes go to die