Drilling holes in various materials is the most frequent operation in plumbing, so the choice of high-quality and suitable consumables and equipment is quite a responsible task. There are about two dozen different types of drills that differ in purpose and principle of operation, so I suggest that you familiarize yourself with the most popular of them.
Twist drills for metal
A good set of twist drills for metal and wood. Made of high speed steel 42 with a high content of cobalt (hardness 68-70 HRC), therefore they have high strength. Top coated with titanium nitride for protection. Supplied in a convenient storage box. The reviews are very good.
Twist drills for wood
A cheaper version of twist drills. They are made of milder steel with 5% cobalt content, but despite this they are also suitable for metal. They are much better than the «plasticine» that is massively sold for a penny on the site. I would still recommend using them purely for soft materials: wood, plastic, non-ferrous metals
Spiral mini drills
Small drills for precision work. Designed for wood, plastic and soft metals such as aluminium, copper. They showed themselves perfectly in conjunction with a drill (dremel). They are inexpensive, so you can not save them. The main advantage of such a set is its cost — they felt that the drill was dull, they immediately threw it away. With branded expensive drills, such a trick will no longer work, so you have to sharpen them. Great for drilling mounting holes.
These drills are designed for drilling large holes in thin-walled sheet materials. They are very convenient to use, since there is no need to rearrange larger diameter drills each time. The set is much cheaper. I advise you to give preference to drills with a spiral groove, they most effectively remove chips.
Another option for drilling large holes, but in one pass. These crowns are designed for metal work. I have similar ones, to extend the service life I recommend adding a little oil. There are also core drills for concrete, tile and soft materials such as wood and plastic.
Drills are designed for proper drilling when accuracy is a priority. The drill has a main thin cutting part, as well as tapered cutting edges for countersinking holes for large diameter drills. This ensures maximum quality and accuracy of drilling, as well as strict perpendicularity. The seller has several options to choose from.
Drills for concrete
Inexpensive set of the most popular concrete drills. Of course, they lose to concrete drills in all respects and are only suitable for brick work, but for the most part because of the impact force of the tool. Can be used with drills or impact drivers. The end of the drill has a carbide tip.
Drill bits for tiles
Very useful drills when renovating a bathroom. They have a spear-shaped shape and a special sharpening. You need to work with them carefully and monitor the temperature, if necessary, cool with water. Mainly used for drilling holes in glass, tiles. On porcelain stoneware, the service life is reduced significantly.
Forstner drills are used when working with wood for drilling non-through holes. The most popular application is furniture production, where materials such as MDF, plywood and others predominate. The design of the drill has a pair of cutting elements and the main tip, with which the drill is centered.
These drills are designed for drilling relatively large holes in chipboard, MDF, plywood or wood. The drill has a trapezoidal cutting part with a sharp end and sharpened sides. They have a number of undeniable advantages, which is why they are so in demand by masters. On the seller’s page, you can choose the desired drill diameter.
These are the most popular types of drills. I’ll tell you about the less popular ones in the second part.