Around Roughing End Mill: A Complete Guide - rough end mill
It’s easy to spend plenty of time researching for your next drill, but it’s just as important to find the very best drill bits for your project. That’s because when it comes to drill bits, all things are most certainly not equal.
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The set is housed in a high-quality case which, despite being slightly tricky to prise some of the bits out of, is clearly labelled and sensibly laid out. The metal drill bits are HSS, the wood bits have sharp brad points, and the spade bits are titanium coated and have a square shaft to reduce slippage in the chuck.
For a start, drill bits are made from a number of different materials. And then the shape of the cutting face can be radically different depending on the material it’s designed to drill through. When you factor in price, the range of sizes available within a set, and the brand, the choice can be bewildering.
Cobalt drill bits are much harder at higher temperatures making them good for drilling through stainless steel and other hard materials, though they are usually way in excess of what most DIYers need.
When you think of a drill bit, most likely, a standard twist bit will spring to mind. These are suited to drilling metal or plastic. They have a sharp tip and the twisted grooves along the length to allow material to be drawn out of the hole to help keep the bit straight.
Toughness is paramount when drilling into metal because the heat generated can easily spell the end for cheap drill bits. Not so here, as this set from Draper sees the HSS straight shank bits coated with long-testing and tough titanium nitride. They’re likely to last longer, and they will not get lost as they come in a soft-grip plastic case which is clearly labelled, making finding bits and returning them to their correct slot a simple task. It’s also finished in Draper’s trademark blue, making it easier to spot at the bottom of a tool bag.
The bits are stored in a fairly tough plastic case, which can also function as a stand to make selecting the correct bit easier. Each bit is clearly labelled in the case too. The round shanks are suitable for use in the majority of drills with a three-jaw chuck.
Smaller diameter drill bits tend to be easy to break, so it’s a helpful touch that Draper has doubled up on the 1.5, 2.0, and 2.5mm bits. And the inclusion of a 3.2mm bit, in addition to the 3.0 and 3.5mm bits, is helpful too.
We’re looking at the more commonly-used drill bits here and, to make the choice easier, we’ve broken them down into the type of materials they’re designed to drill through. Plus we’ve thrown in our top drill bit set that covers all the main options. We’ve looked at online reviews and ratings from a range of retailers to deliver our verdict.
But it’s definitely worth spending the time and doing your homework because there’s nothing more frustrating than not having the correct size or type of drill bit to hand when you need it, or to find the bits disintegrating right in the middle of a delicate job.
Value is the name of the game with this set from Bosch, at just a touch over £1 per drill bit. If there’s a letdown, it’s that there’s no 9mm bit in the set, but all the other main sizes are covered so it barely harmed the near-perfect score among Amazon customers. Each bit has a sharp brad point for improved accuracy, and the shoulder-cutters on the leading edge of the grooves are designed to reduce tear out.
Generally speaking, DIYers will end up buying a drill bit set, rather than a single bit – although there are exceptions, particularly for specialty jobs such as when a masonry drill bit is required – so that will already have a few of the main sizes covered.
Key specs – Number of bits: 50; Material: titanium nitride-coated, carbide-tipped; Sizes: 1.5-6.5mm (metal), 4-10mm (masonry), 4-10mm (wood); Case type: plastic carry case
If you’re drilling a hole for a screw in wood, you will need a drill bit that’s slightly smaller than the screw you’re planning to use so that the screw’s thread will tap into the material. If you’re drilling a hole more than 10mm in diameter, you may be better off with a completely different, more specialist type of drill bit, like a Forstner bit, a spade drill bit, or, for much better holes, a hole saw.
The odd breakage aside, the Bosch 50-piece X-Line set could be the only box of drill bits you will ever need. It covers the majority of common sizes you would need for drilling wood, metal, and masonry, plus it includes screwdriver bits (and an extension bar), a countersink bit, three sockets, two spade bits, and a gauge to check the size of the bits. It even comes with a snap-off knife.
Wood drill bits are usually the easiest to spot in your set because they often have a very sharp pointed tip on the end – a brad point – which allows the bit to grip the wood, without moving around, to start the hole. They have a sharp double-bladed thread which allows the drill to work its way through the wood quickly.
The carbon steel shaft and tungsten carbide tip offers the sharpness and abrasion to cut through tougher materials. According to reviewers, the ease with which these Wickes items cut is impressive, especially given the price of these specialist bits.
You’ve usually only got one chance when drilling into glass or tiles – with the time cost and monetary expense of replacing breakages, precision matters. Many glass and tile drill bits just look like regular twist drill bits, but this trio from Wickes are spade, or spear, shaped. While spear-tipped bits are generally more prone to breakage than twist bits, that can often be preferable to breaking a tile.
Most of the drill bits you’re likely to encounter will bear the abbreviation HSS, for high speed steel. It’s a steel, alloyed with a range of other metals, designed to withstand the extreme temperatures generated by drilling through harder materials at high speed, hence the name. But, despite the high breaking strength they exhibit, they’re also brittle and don’t offer much resistance to bending. Which means it’s easy to snap thinner bits with even the most innocuous of impacts.
And carbide – usually tungsten carbide – is a similarly tough material, and is commonly used in the manufacture of masonry drill bits.
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