{"id":54753,"date":"2023-03-02T10:50:21","date_gmt":"2023-03-02T08:50:21","guid":{"rendered":"https:\/\/www.lion-test-sites.co.za\/mica-new\/?p=54753"},"modified":"2023-06-05T14:56:59","modified_gmt":"2023-06-05T12:56:59","slug":"all-about-drills-and-bits-part-2","status":"publish","type":"post","link":"https:\/\/www.lion-test-sites.co.za\/mica-new\/all-about-drills-and-bits-part-2\/","title":{"rendered":"All about drills and bits and more: Part 2 drill bits"},"content":{"rendered":"\n

Last month we took you through the various types of drills you are most likely to find on the market and most likely to require at some stage or other for tasks around the home and in the workshop. Now to the drill bits themselves\u2026<\/p>\n\n\n\n

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  1. To begin with, a very useful item to have is a drill bit measuring plate such as this one. It is used to establish the diameter of any drill bit ranging from 13mm\u00d8 down to 1mm\u00d8 useful when you have a number of drill bits that have hard-to-read size indicators or for which the packaging in which they came has long gone.<\/li>\n<\/ol>\n\n\n\n
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    1. The plate is easy to use. Take the drill bit and insert it into the nearest size holes. If it doesn\u2019t fit in one, go to the next size up and see if it fits there. If not, up one again. If it was loose in the first hole, try the next smaller hole.<\/li>\n<\/ol>\n\n\n\n
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      1. In this case, it passed easily into the 6.5mm\u00d8 hole, with some play, but was just too large a diameter to pass into the 5.5mm\u00d8 hole.<\/li>\n<\/ol>\n\n\n\n
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        1. So it was a 6mm\u00d8 drill bit. Success! Note:<\/u><\/strong> You could conceivably use a drill measuring plate to check the diameter of a masonry bit, but ensure that you measure across the tungsten-carbide inserts at the tip of a masonry bit and not the shaft (also sometimes referred to at the shank) as the tungsten-carbide inserts often stand proud the shank diameter.<\/em><\/li>\n<\/ol>\n\n\n\n
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          1. A range of Titanium Nitride-coated (TiN) High-Speed Steel (HSS) ranging in size from 1mm\u00d8 up to 10mm\u00d8. HSS bits are a popular choice for drilling into soft metals such as steel, aluminium, brass or copper, and into wood, plastic and fibreglass. Drill bits of this type are sometimes referred to a twist drill bit or fluted drill bit, as they have flutes which are designed to remove material from the drill hole.<\/li>\n<\/ol>\n\n\n\n
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            1. The parts of a typical HSS drill bit. Nomenclature can possibly vary from one manufacturer to another, but the basics are all the same. The point is self-evident that’s the part that does all the hard work. The flute removes loose material created by the tip from the hole. The land is a slightly raised portion of the body, so that there is a little clearance between the hole being drilled and the body of the drill bit (the body clearance). This ensures that the shaft\/shank is able to rotate freely in the hole being drilled without adding a frictional impediment to the bit’s rotation. The tang, or course, is the part of the shaft\/shank that is gripped in the drill’s chuck.<\/li>\n<\/ol>\n\n\n\n
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              1. A little more detail on the actual tip. A very common angle for the point angle is 118\u00b0. The part behind the cutting lip is its flank and the part of the bit immediately below it is the face.<\/li>\n<\/ol>\n\n\n\n
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                1. An assortment of stubby double-ended drill bits. They can cost a little more, but as you can see you get double the use out of them. These HSS bits are often used to drill through extruded aluminium and sheet metal as they do not drill very deep holes. Typical sizes range from 2mm\u00d8 up to 6mm\u00d8.<\/li>\n<\/ol>\n\n\n\n
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                  1. When seating a stubby bit, use the marking at the midpoint to correctly set the drill in the chuck the jaws of which should NEVER be clamped on to the cutting section the flutes as not only could the bit tend to be clamped at a slight angle, but the flutes will be damaged.<\/li>\n<\/ol>\n\n\n\n
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                    1. Stubby bits are usually sold in packs, ranging up to about 10 pieces when in the smaller diameters when you consider you are getting an effective 20 bits in a packet of 10, it can be a rather good deal bearing in mind, of course the point made just above about the depth of hole these bits can be used to drill.<\/li>\n<\/ol>\n\n\n\n
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                      1. Drill sets in this case from 10mm\u00d8 down to 1mm\u00d8 in increments of 1mm are available in a range of drill types and size ranges.<\/li>\n<\/ol>\n\n\n\n
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                        1. These screw pilot sets are available in sets of 4 or 5 and bits are not sold individually, so if you break one, you will need to buy another set. Having said that, they are not expensive and are good value for money. Their tangs are of sintered metal pressed into a hexagonal cross-section of 6.35mm\u00d8. (Sintering [also known as frottage] is the process of forming a solid mass of material by compacting it under pressure or heat without melting it to a liquid state]<\/em>). Their tang shape makes them very useful drill bits for use with cordless drill drivers, but obviously, can also be used with mains-powered machines. Their sizes are as follows for the four-pack:\n#6 (screw gauge) x 2.3mm\u00d8 drill\n#8 (screw gauge) x 2.8mm\u00d8 drill\n#10 (screw gauge) x 3.0mm\u00d8 drill\n#12 (screw gauge) x 3.6mm\u00d8 drill\nThe pack of five has bits with the following diameters:1.5mm\u00d8, 2.5mm\u00d8, 3mm\u00d8, 4mm\u00d8 and 5mm\u00d8. The four symbols on the packaging indicate that these bits are suitable for use on copper (Cu), Nickel (Ni), Zinc (Zi) and Mild steel (Ms). However, they are also suitable for use on aluminium, wood, plastic and fibreglass.\n#6 (screw gauge) x 2.3mm\u00d8 drill\n#8 (screw gauge) x 2.8mm\u00d8 drill\n#10 (screw gauge) x 3.0mm\u00d8 drill\n#12 (screw gauge) x 3.6mm\u00d8 drill\nThe pack of five has bits with the following diameters:1.5mm\u00d8, 2.5mm\u00d8, 3mm\u00d8, 4mm\u00d8 and 5mm\u00d8. The four symbols on the packaging indicate that these bits are suitable for use on copper (Cu), Nickel (Ni), Zinc (Zi) and Mild steel (Ms). However, they are also suitable for use on aluminium, wood, plastic and fibreglass.\n\n