of fasteners such as nuts, bolts and Torx fittings, often in places too tight for ordinary spanners or where the fastener has seized and a spanner simply slips off. Whatsmore, when used with a torque wrench or angular gauge, they allow fasteners to be set to the exact tightness recommended by the vehicle manufacturer. This is vital when tackling components such as engines, clutches and gearboxes where the torque setting of many of the fasteners is critical. Given that a socket set is at the heart of the mechanic's tool kit, perhaps it's no surprise that nowadays there are a bewildering range of them available. Open any tool catalogue and off the page will fly buzz words such as "1/2" Drive, Bi-Hex, Hex, Chrome-Vanadium, Wall Drive, Impact, Deep Impact, Professional, Lifetime Warranty" to name just a few in a calculated attempt to part you from your cash. But what do these actually mean and what distinguishes a good set from a bad? Do you simply buy the most expensive set available and trust to the maxim "you get what you pay for"? Well, paying top whack would certainly get you quality, but you could be talking well overyour budget for a comprehensive, top of the range brand name set!! At the other end of the scale, a cheapset. will get you a 72-piece set from a well-known catalogue store (we reckon you couldn't make them from chocolate for that much!). In this feature, we set out to explore and explain the features and benefits that you should look for when selecting a socket set. We will start by matching quality to your requirements and then explore the bare essentials, building up a picture of the core components in a good socket set, as well as looking at the accessories that can be added as need arises. OK, so what does a socket set need to be good quality? Well, that all depends on the job that you want to do with it. For instance, for fixing things around the home, such as shelves, cupboards and, for the more adventurous, washing machines etc, then even a cheap and nasty set will probably suffice. This is because fasteners around the home don't rust up and seize and aren't usually tightened to high torques characteristic of larger, high strength nuts and bolts on your average 4x4. If your requirement is for a home DIY set, that will not be used on your vehicle, then use our guide to identify what it should contain, but don't get too hung up on the actual strength and longevity of the items within. However, for the rest of us, it is essential that our socket set meets certain quality standards - both from a practical point of view (a broken socket is useless), and a health and safety point of view (the sudden failure of an item can lead to broken fingers, wrists and eye injuries, not to mention bloodied knuckles). A good quality socket set will contain a variety of actual sockets, some means of turning them (a ratchet handle, T-bar, spinner handle) and one or more extension bars, to include a universal joint. Now let's look at each in more detail. Firstly, the sockets themselves should be made of chrome vanadium steel, since this gives exceptional strength and durability. Good quality sockets will also be plated with nickel chrome for maximum resistance to corrosion, and to give a high quality appearance. They should have their size (typically referring to the width across the flats of the fasteners they fit) marked on them and often include manufacturer's name alongside. The design of the business end of the socket, the bit that fits over the nut or bolt, is critical to the effectiveness of the socket. Simple sockets have a bi-hex, 12-point design and, although reasonably effective, can lead to rounding-off of seized or low strength fasteners (rounding-off means metal is torn from the fastener head before it turns, making subsequent removal extremely difficult because the fastener has now lost its original shape). <<Picture (Metafile)>> Simple and cost-effective bi-hex sockets can be problematic with soft or seized fasteners To combat the problems of "rounded" fasteners, a hexagonal, 6-point design is preferential. Six-point hex designs also allow for a slimmer wall thickness, giving the socket a reduced overall diameter and hence easier access to recessed or tightly confined fasteners. Look carefully at the 6 'corners' within a hexagon socket; these should be rounded in profile to ensure that the turning force from the socket is transferred to the flanks of the fastener and not its weaker tips. This also has the advantage of permitting an easier fit over a fastener that already has damaged tips from previous attempts to loosen or tighten it. <<Picture (Metafile)>> <<Picture (Metafile)>> Rounded tip profiles ensure turning forces are transferred to the stronger flanks of the fastener Also available are so-called surface drive sockets that retain a 6-point profile but have a special shape to again drive the fastener flanks (including worn or damaged ones) with reduced wear even at very high torques (the torque is simply the turning force transmitted through the socket). <<Picture (Metafile)>> Surface drive sockets can transmit very high torques, even on damaged or worn fasteners We recommend that you only buy 6-point hex (with rounded tip profiles) or 6-point surface drive sockets, since these will not round off or wear the heads of fasteners that require very high torques (either to tighten them down or to loosen them off, especially when seized). Six-point sockets must always be used on small fasteners less than 13mm or 1/2" across the flats, since these are frequently not made from high strength, high tensile steels, but rather weaker steels, prone to rounding off, since they are not usually subjected to very high loads. Sockets can also come with a whole variety of Bits fitted in them including Torx head, common screwdrivers, Allen or hex heads and these are a handy addition to any set so treat them as a definite bonus. <<Picture (Metafile)>> Sockets can come ready fitted with a variety of bits, a very handy addition to any set Once fitted over a fastener, the socket itself has to be turned by some means. Some sockets have a pattern knurled onto them and this allows them to be turned by hand when the fastener itself is loose - a very useful feature. For small fasteners, a simple hand spinner tool also enables rapid turning and helps prevent over-tightening. <<Picture (Metafile)>> <<Picture (Metafile)>> A knurled pattern on a socket is a big bonus for rapidly turning a loose fastener by hand. The hand spinner also shown helps avoid over-tightening since it can only apply limited torques For transferring larger torques into the socket, a tool such as a ratchet handle, T-bar or L-handle, is inserted into its square end and may take a variety of forms with various size of square drive corresponding to the socket. Generally speaking, the larger is the square drive in the end of the socket, the higher are the forces that socket is designed to transmit. For the 4x4 mechanic, sockets are available with a 1/4" square drive, 3/8" square drive, 1/2" square drive and 3/4" square drive. Each has its application as follows: 1/4" drive Essential for small fasteners of 10mm (11/32") diameter across the flats, or less. A good, basic set should include all the following sizes: Metric 4, 5, 6, 7, 8, 9, 10, 11, 12, 13mm, Imperial 5/32", 3/16", 7/32", 1/4", 9/32", 5/16", 11/32", 3/8", 7/16", 1/2" AF. Although the ratchet handles, T-bars and hand spinners are much smaller, it is still possible, and indeed very easy, to over-tighten small fasteners so extra care must be taken at these sizes. 3/8" and 1/2" drive Arguably the choice of most professional car mechanics, 3/8" drive sets are available in a very wide range of sizes and varieties, typically from 10mm up to 22mm. Beyond 22mm, the torques required on high tensile fasteners can exceed those recommended for 3/8" drive systems. For most 4x4's, especially big ones, the size, frequency of seizure and, dare we say it, level of abuse suffered, leads us to recommend that inherently stronger 1/2" drive systems are selected rather than their 3/8" drive counterparts. Having said this, a top quality 3/8" drive system is stronger than a poor quality 1/2" drive system, so make sure you are buying like for like, good quality stuff. A good, basic 1/2" drive set should include all the following sizes: Metric 10, 11, 12, 13, 14, 15, 16, 17, 19, 21, 22, 23, 24, 27, 30, 32mm, Imperial 3/8", 7/16", 1/2", 9/16", 5/8", 11/16", 3/4", 13/16", 7/8", 15/16", 1", 1 1/16", 1 1/8", 1 1/4" AF. Additionally, it should include a 14mm spark plug socket. 3/4" drive For big 4x4's, there will be an occasional need to deliver very high torques to certain fasteners. Classic examples are seized wheel nuts (or those seriously over-tightened courtesy of some inexperienced fitter with an air-powered impact wrench), crankshaft retaining bolts and, often seized or corroded, suspension components. For this really heavy duty work, a 3/4"drive socket is a must. Don't be tempted to buy one of the numerous cheap and nasty 3/4" drive "everything included" sets that are currently starting to flood the market. Remember that it is likely that you will be applying very high torques through these larger sockets and therefore the risk of injury, should they fail, is more severe. A decent 3/4" drive ratchet handle costs more than a cheap complete set, and the sockets themselves each. We recommend that you buy individual 3/4" drive sockets as specific need arises (you will probably need no more than 3 or 4 sockets). Furthermore, given that you will only need these for very occasional use, a ratchet handle is an unnecessary expense. A far better solution is to buy a much less expensive sliding T-bar or an even more cost-effective simple L-handle (high quality 3/4" drive L-handles are available from us and are hard to find elsewhere; we have to import them specially!). <<Picture (Metafile)>> A simple L-handle is the most cost-effective means of applying torque to 3/4" drive sockets One drawback of any socket is the fact that its depth may be too small to reach a fastener that has been tightened down over a long stud. In these situations, so called deep drive sockets are available which, as the name suggests, have an increased depth to cope with protruding studs or, in the case of small fasteners, deep recesses. Better quality, comprehensive socket sets come with several popular sizes of these included. <<Picture (Metafile)>> A deep drive socket can cope with protruding studs and narrow recesses As mentioned, sockets are attached to ratchet handles, T-bars and L-handles during use. Good quality sockets will have small grooves machined into the square recess, and into this groove locates a spring-loaded steel ball set into the ratchet handle etc. This groove and spring-loaded ball stops the socket slipping off the ratchet handle during use. A word now about ratchet handles. These are the real work horses of any socket set and have to cope with repeated use and very high torques. A huge variety of ratchets are available, but a few features must be considered essential. Firstly, the ratcheting mechanism itself should be reversible by means of a small lever or knob, and the spring-loaded ball in the square drive should lock in place until a push button at the opposite end of the square drive releases it. Thus, the button must be pushed whilst the socket is fitted onto the ratchet, and it must not be possible to pull the socket off until the button is pushed again. Whilst you are examining the business end, it should have a good thickness of metal around it, and should be forged in one piece with the handle. Better quality sockets can be fitted with service kits when the ratcheting mechanism is damaged or (after an awful lot of use) worn. Check that service kits are available from the manufacturer and that the ratchet head is fitted with small removable fasteners (typically Phillips head screws) to allow dismantling. The actual ratcheting mechanism itself is a critical part of the tool, since it contains the moving parts and does all the hard work. The number of gear teeth within the ratchet will determine the amount the handle has to be moved before the ratchet will click and allow the fastener to be turned. In very confined spaces, the smaller this movement is, the better, and this corresponds to a higher number of gear teeth. Typically, ratchets can come with 24, 30, 45 and even 60 gear teeth, and for general automotive use, we recommend at least 30 gear teeth. Try the ratchet handle by holding the square drive peg and seeing how far you have to swing the handle before you feel it click. With 3/8" drive or larger ratchets, try turning the square drive peg with your thumb alone whilst holding the ratchet in your other hand. Weaker mechanisms will turn easily with little resistance and will not have a good, positive click as the peg turns. The other end of the ratchet handle can sometimes be fitted with a rubber or plastic comfort grip to reduce fatigue on you during use. Despite their ruggedness and durability, don't use ratchets as impromptu hammers or overload them by virtue of a heavy boot or length of pipe! <<Picture (Metafile)>> A good quality ratchet handle will have a reversing lever, push button socket release and one piece handle and head. Note the Phillips head screws in the head, which permit dismantling for cleaning or fitting of service kit Occasionally, ratchets will stop ratcheting and will wave backwards and forwards with no positive click. More often than not, this is because dirt, debris or thick oil or grease has worked its way into the mechanism. Nine times out of ten, stripping the mechanism down and cleaning it with a mild solvent will cure the problem. Failing this, go and buy one of those service kits we mentioned. Where maximum torques are to be applied to very stubborn fasteners, a ratchet handle should not be used. In these instances, a simple T-bar, L-handle or breaker bar should be used since they do not have moving parts susceptible to damage. Once the fastener is loose, you can swap back to the ratchet to permit rapid turning. <<Picture (Metafile)>> <<Picture (Metafile)>> Breaker bars, T-bars and L-handles must be used on very stubborn fasteners to avoid overloading ratchet handle mechanisms Sockets can also be fitted to powered wrenches known as impact wrenches. These can derive power from either a compressed air supply or a rechargeable battery pack. Powered impact wrenches can deliver very high torques and do so by delivering powerful 'hammer' blows to the socket. Because of this very high loading, ordinary hand sockets, no matter how good the quality, MUST NOT be used since they could shatter or split causing injury. Instead, special, very heavy duty sockets called Impact Sockets must be used and even then, eye protection MUST be worn at all times. Impact Sockets have much thicker walls than ordinary hand sockets and really high quality ones are made of Chrome Molybdenum Steel as opposed to Chrome Vanadium Steel. Impact Sockets must also be retained on the powered wrench with either a pin or special clip since it is imperative they do not slip off. Impact sockets are not plated with Nickel Chrome, unlike hand sockets, since this will not withstand daily arduous treatment in a powered wrenched. Instead they have a characteristic matt black finish. It is permissible to use an impact socket as a hand socket, driving it with either a ratchet or bar. In fact, if subjecting the socket to very high loads (such as those seized wheel nuts again), then an impact socket is preferable. Note though that the increased wall thickness may cause access problems, especially on modern alloy wheels so, try before you buy. <<Picture (Metafile)>> An ultra tough, thick walled impact socket MUST be used in any powered wrench and suitable eye protection worn. Note the characteristic matt black finish Nowadays, impact type sockets are also available with an extended, flexing shaft. These shafts are specially made to flex at a specific torque (tightness) and so prevent over-tightening with a powered wrench (the flexing absorbs the hammer blows). These are called torsion bar sockets and are colour coded according to the torque at which each flexes. Ask your garage or tyre fitting shop if they have flexing torsion bar sockets, since these are a sure sign of a professional outfit and used properly will mean you won't drive away with wheel nuts that need a gorilla to subsequently undo them! Note torsion bar sockets cannot be used to achieve specific torques by hand since they rely on the non-constant impulse action of a powered wrench. <<Picture (Metafile)>> Torsion bar sockets are a godsend to tyre fitters and, used properly, ensure that wheel nuts are not over-tightened by powered wrenches Having dealt with the many variants of sockets and drivers available, it's also worth mentioning a few other accessories that no self-respecting socket set should be without. Firstly there's the simple extension bar. These are available in a variety of lengths and are invaluable for extending a socket down into awkward recesses or tight spaces. Typical lengths are 100mm (4"), 150mm (6") and 225mm (9"). You should have at least one extension bar, and preferably all three, for maximum usefulness. Hand in hand with the extension bar goes the wobble bar, a sort of flexible equivalent. Wobble bars enable the drive to be kinked over to avoid obstructions. Universal joints perform a similar task to the wobble bar. These clever little devices enable the socket, extension bar or ratchet to be kinked over in order to avoid any obstructions that hinder access. Beware though, they are the weakest link in the chain and care must be taken not to load them excessively. Never use ordinary extension bars and universal joints in conjunction with impact sockets in powered wrenches, since this would be extremely dangerous. Instead you MUST buy specially designed impact grade extension bars and universal joints (yes they are available) and wear eye protection. <<Picture (Metafile)>> <<Picture (Metafile)>> <<Picture (Metafile)>> <<Picture (Metafile)>> >From TOP to BOTTOM, an extension bar and a wobble bar or a Universal joint are 'must haves' in an automotive socket set Warranties It's worth saying a few words about warranties. Good quality socket sets and accessories should always come with a warranty and these typically range from 10 years to lifetime. Always keep your proof of purchase and any reputable tool supplier will not quibble at the occasional claim. However, whilst good warranties elevate sockets sets out of the 'chocolate watch' status they do not guarantee that you will never break something if you are careless enough to abuse it. So don't use excessive force such as your boot and don't use a socket set in conjunction with a hammer of any description!! For really tough jobs use a bigger drive size (3/4") together with an impact socket and a T Bar, breaker bar or L handle (or if you are lucky enough to have one, a powered wrench). We hope you now have enough information to distinguish a good socket set from a bad and decide just what type best suits your need.
********************************************************************** This message and its attachments may contain legally privileged or confidential information. If you are not the intended recipient, you must not disclose or use the information contained in it. If you have received this e-mail in error, please notify the sender immediately by return e-mail and delete the e-mail. Any content of this message and its attachments which does not relate to the official business of Eraring Energy must be taken not to have been sent or endorsed by Eraring Energy. No warranty is made that the e-mail or attachment(s) are free from computer virus or other defect. ********************************************************************** [Non-text portions of this message have been removed]
