用于不同工作的钻头

An electric drill without bits is like a bow without arrows. And the better the bit (or arrow, I suppose), the better the result.

像锯割一样，钻头有很多味道，适合钻取任何事情。Depending upon your needs, you’ll probably want to have several different types on hand, but a good starter set of drill bits should include at least a small index (perhaps ten drills) of twist drills and a set of spade bits (perhaps six pieces).

扭转钻头。Twist drills were invented by a fellow named Morse, and some machine shop types refer to a twist drill as a Morse drill. A twist drill has a cylindrical steel shank and a pointed tip. A pair of helical flutes (sometimes called chip channels) run along two-thirds of its length, twisted around the shank like the stripes on a barber’s pole.

切削刃（称为唇缘）位于凹槽的尖端，其中槽的嘴相遇。长笛本身没有钻孔，但清除孔中的碎屑，以防止钻头束缚或减慢废物。

大多数扭转钻头的尖端以59度角接地，使其能够有效地降低金属;当然，他们也会切割木头。碳钢比特专门用于钻孔，不应用于切割金属。扭转钻通常以尺寸的尺寸范围从达到半英寸直径的十六分之一。大于四分之一英寸的大多数扭曲钻头减少了四分之一英寸的柄部。

铲子。这些位看起来像他们的名字表明：每个钢轴终止于铲形刀片。铲子是平的，中心有一个尖锐的点。该点充当指导，以孔为中心并引导方式，但是钻孔的大部分实际上由珩磨的切削刃在铲子的肩部完成。

不要试图用这个削减金属。铲子是木材，胶合板和一些塑料，并用惊人的精度迅速切割。仅以高速使用它们，以防止钻头在工件中捕捉，并试图从掌握中拧紧本身。在直径四分之一英寸至1和半英寸之间的范围内发现铲子。

布拉德点钻头。Designed specifically for cutting wood, brad point drills are a cross between spade bits and twist drills. The shaft of the drill resembles the twist drill, with fluted chip channels spiraling around the shaft. Most of the cutting is done at the lips of the channels, but the hole is actually started with a smaller-diameter brad point (or spur) that leads the shaft into the hole. Two other spurs at the outer edge of the drill help keep the drill on line. The channels are usually cut deeper on brad point drills that on twist drills, in order to clean out the wood debris.

柜台钻头。特别制作的位销售用于木螺钉的钻钻孔。柜台钻头具有型材以匹配螺钉的形状：沿着螺钉的长度逐渐逐渐钻孔的孔，然后放大，允许将螺钉的头部（埋藏）进入木材。

可以使用可调节的停止项圈购买一些柜台钻头，可以设置为在固定深度下停止钻取进度。还可以购买另一种钻头，称为插头刀具。它用于切割同一木材的小塞子;然后可以将插头插入螺钉后沉入螺旋孔中以沉积它们的存在。

洞锯。孔锯钻头由两部分组成,曼rel and the blade. The mandrel is a shaft to which the blade is attached; the mandrel is gripped by the chuck of the drill like the shaft of any other bit. The blade is a hollow cylinder with teeth on its top edge.

Hole saws handle the work in the gray area between the smaller holes best made with twist or spade bits (those roughly an inch in diameter and smaller) and larger ones (three or four inches and up) that are sawn most easily with a saber saw. Hole saws cut wood, plastics, and a variety of metals, including iron, steel, and aluminum. Hole saws are invaluable when installing piping, tubing, conduit, and cables.

福尔斯特纳位。These clever bits drill holes with virtually flat bottoms. Rather than having a steeply ground tip that is followed by angled cutting edges, the Forstner bit is guided by the rim. Channels in the drill clear the hole of chips and dust. The resulting hole has a virtually flat bottom, marred only by a 1/32-inch hole at center where the starter spur of the drill is located.

Forstner Bits相对昂贵，而且对大多数工作都不是必要的。然而，它们对其他人至关重要，例如必须凹陷到圆孔中的安装铰链，仅延伸穿过门窗框。（如果您要以相同目的使用Spade位，它的点可能会突出到另一侧，淡化表面。）

砌体位。这些设计用于钻混凝土，砖，石材，石膏和其他砌体材料，这些材料将大多数钻头迅速沉闷或骨折。砌体钻头具有连接到钢轴的碳化钨尖端。

这些位用于在砌体中切割相对小的孔（通常是四四四分之一英寸或更小），以便运行电缆或管道，或用于将塞子或屏蔽安装到砌体上的挡板或护罩。

砌体位应以相对缓慢的速度驱动，以防止它们过热。当钻时，定期从孔中取出钻头，以消除松散的灰尘和碎屑。

其他演习。Among other options are corner bits (they resemble spade bits, but the sides as well as the face of the drill are sharpened); glass bits; and mixing bits, large and small, for paint, plaster, and other liquids.