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METRIC AND IMPERIAL SOCKET SETS

METRIC AND IMPERIAL SOCKET SETS

by James Stanbury, 16th August 2016

There are still plenty of old Land Rovers out there with imperial nuts and bolts, so James Stanbury checks out seven 3/8-inch drive socket sets that cater for both metric and imperial sizes. But which one will be best?


Look around any professional garage and you’ll find most mechanics use 3/8in drive socket sets as their main tool of choice. Although 3/8in drive socketry is only slightly more compact than 1/2in drive stuff, that slight reduction in size makes a big difference in use. Once accustomed to 3/8in drive tooling, 1/2in drive stuff feels big and clumsy by comparison.  Also, modern 3/8in drive sets tend to be up to the job and affordable – unlike some grotty imported sets in the early 1980s.

So, having made the case for 3/8in drive tooling, the next issue is the thorny one: do you choose metric, imperial, or both? Well, if you only work on modern vehicles, metric is the obvious answer. But as many Land Rover enthusiasts have a penchant for older models, it’s perhaps not such a great idea to go down the metric-only route. However, sets that cater for imperial and metric tend to do it in different ways. Some take the obvious route: providing so many metric sockets, and a similar number of imperials. Others are a little smarter, in that some common sizes are catered for by just one socket because the AF imperial and metric sizes are practically identical – 3/4in and 19mm is one obvious example. And there are several other sizes, where the difference in actual size – between the metric and imperial sockets – is so minute that the tolerances used when making the tools actually exceed those differences. In other words, it’s pointless making a dedicated imperial and metric socket because it could actually work out that the metric fits the imperial better, or vice versa.

The third option used in imperial/metric sets is dual-sized sockets, where each socket is both a metric and an imperial size. Traditionally, such tools have been viewed suspiciously. Understandably, there’s a degree of scepticism about whether a jack of all trades socket can grip anywhere near as securely as a single-size-only tool. But before writing such products off, bear in mind that hexagon sockets always grip significantly better than bi-hexagon sockets (which have a similar pattern to ring spanners). And as many dual-size sockets use a modified hexagon pattern, it’s possible that, whilst a dual-size hex socket won’t grip quite as well as a single-sized hex socket, it may well grip far better than a single-sized tool with a bi-hex drive. 

THE TESTS:

VERSATILITY: We examine the range of metric and imperial sizes and award up to four points to the most comprehensive selections. An extra point is awarded if a set can tackle other bolt configurations, such as hex, Torx, or star. A further two points if the set contains deep sockets that cater for at least 90 per cent of the sizes that the standard-height ones do.
GRIP: Anybody who’s ever tried removing brass exhaust nuts off old and rusty metal studs will know that they round off very easily. Using studs and dedicated hex sockets, we tightened a selection of brass nuts up to various torques. To get both the points, a set had to remove all of our tightened-up 1/2in AF brass nuts.
WALL THICKNESS: We measured the wall thickness of the 13mm socket in each set. Only if it was 1.5mm, or less, did it get this extra point.
ACCESSORIES: To get the two points available, the ratchet mechanism had to have in excess of 50 positions.  We then gave another point to all sets with more than two extensions, and another point was available to sets we felt provided better than average accessories – in terms of quantity 
or usefulness.



WHAT'S IMPORTANT?

VERSATILITY: As a minimum, we expect all of our sets in the group to cater for both metric and imperial sizes. But we’re also keen to see products capable of dealing with newer fasteners such as star. And we mustn’t forget that other type of fastener that can often outfox even the best socket set – namely nuts at the bottom of long studs. Deep sockets are obviously advantageous in this situation.
 
GRIP: As mentioned in the introduction, several types of socket are available that can, allegedly, manage more than one size per socket. But common sense suggests that these ultra versatile tools surely cannot grip as well as dedicated hex sockets. So resolutely testing all of these products for grip is a major part of this feature.
 
WALL THICKNESS: Another, often overlooked, factor that sometimes prevents socket use is when the socket’s wall is simply too thick. Generally this is because a lower grade of steel has been used, so more “meat” is needed to handle the stress and strain. All too often, though, vehicle manufacturers put nuts and bolts right up against manifolds, and other obstructions. In these cases, thin walls make the difference between the tool being usable or not.
 
ACCESSORIES: The heart of any socket set is its ratchet, and a particularly fine one comes into its own when you can only swing the tool a few degrees at a time. In reality, you can never have enough extensions, and we particularly like the ones with screwdriver style handles – which make removing a semi-loose fastener so much easier than fingers alone. T-handles and breaker bars are a sensible inclusion too, because having one in the set tends to prevent the ratchet being hammered as heavily

KNOW YOUR CONFIGURATIONS:
• Hex sockets – have a simple five-sided drive shape that sits perfectly around a nut or bolt head. Even if the fastener is somewhat chewed away, the socket’s closeness, in size and shape, still usually means it will get the fastener moving. Most heavy-duty impact wrench sockets use hex configuration due to its ultimate grip potential.
• Bi-hex – the pattern usually seen in ring spanners, and actually invented in pre-ratchet days so that a spanner could be re-positioned after only 30 degrees of movement. Whilst that’s still a benefit in spanners, it’s somewhat pointless on sockets –which are almost always driven by a ratchet. Bi-hex has significantly less grip than hex, so it’s always best to buy hex-style socket sets.
• Flank drive – designed to drive a nut/bolt on its flats, rather than on its corners. With bi-hex, this means significantly more torque can be transmitted before the fastener starts to round off. With hex, flank drive is normally used so that a socket can be used on more than one size. And, whilst flank drive hex still easily outperforms bi-hex, it lags behind standard hex in the grip stakes.


^ FRANKLIN XL 3826

COMMENTS: You could easily be forgiven for thinking this is purely a metric set, as there’s no mention of imperial sizes on the packet, case, or on the sockets themselves. But the secret is in the peculiar flank drive hex configuration at the business end of the sockets. In short, for non-metric fasteners, simply pick the socket that fits tightest and – in theory – it will work as well as a dedicated tool. But does it? Well, put simply, yes. These sockets gripped almost as securely as dedicated hex pattern ones, which means that range of 6-24mm (minus 23mm) caters for a whole raft of AF sizes too. The generous smattering of accessories, and the super-fine 72-position ratchet, make this set well worth the money.
PRICE: £52.95
CONTACT: 0114 272 1429
WEB: www.franklin-tools.co.uk
PERFORMANCE: 11/14
IS IT WORTH THE MONEY? 6/6
OVERALL SCORE: 17/20
LRM | BEST BUY

^ SEALEY AK692

COMMENTS:
Sealey takes a unique approach to providing a set that caters for imperial and metric sizes. You see, rather sensibly, it has realised that some metric and imperial sizes are so similar – 10mm and 3/8in, plus 19mm and 3/4in spring to mind – that it’s pointless doubling up. Instead, one hex-pattern socket will grip and drive either size securely. However, on sizes where the nearest metric size is a sloppy fit on an AF fastener – such as 13mm on a 1/2in nut – dedicated AF sockets are provided. This means AK692 caters for 8-22mm, and 5/16-7/8, in standard and deep heights with the minimum of sockets. The sockets themselves are pleasingly well-made and thin-walled too.
PRICE: £64.13
CONTACT: 01284 757500
WEB: www.sealey.co.uk
PERFORMANCE: 9/14
IS IT WORTH THE MONEY? 4/6
OVERALL SCORE: 13/20

^ CLARKE PRO 123

COMMENTS:
First impressions here? We don’t like it! But that’s because we opened the rather snazzy case to find everything everywhere. The case just doesn’t seem to be able to keep its contents where they should be, once it’s closed. That moan aside, we were impressed with the rest. Clarke seems to have taken the term socket set literally, because this is very socket-heavy. Accessories-wise, you get the ratchet and a couple of extensions. The sheer selection of sockets helps to restore the balance though. All are no-nonsense hex drives, and each of the 6-19mm and 3/8-7/8in imperial sizes has its own socket. In fact it has two, because each size is catered for in deep and standard heights.
PRICE: £41.99
CONTACT: 01992 565300
WEB: www.clarkeinternational.com
PERFORMANCE: 9/14
IS IT WORTH THE MONEY? 6/6
OVERALL SCORE: 15/20
^ CLARKE PRO80

COMMENTS: This set is something of a puzzle. It costs little more than the previous Clarke offering, covers the same metric and AF sizes, and also caters for every size in deep and standard height sockets. In fact, at first glance, it seems as though it’s only the case that’s different. Which would be great if it was any better at holding its contents in place than the Pro 123. Sadly, though, it isn’t. So why have Clarke got two almost identical sets, in their range? Well, under closer examination, there are some differences. The sockets are definitely fatter – the 13mm sporting a 1.68mm wall – and the ratchet is down to a somewhat crude 24 position mechanism. So our advice is simple: get the significantly better Pro 123.
 
PRICE: £50.39
CONTACT: 01992 565300
WEB: www.clarkeinternational.com
PERFORMANCE: 6/14
IS IT WORTH THE MONEY? 3/6
OVERALL SCORE: 9/20

^ DRAPER 43592

COMMENTS: There’s no new-fangled trickery with this set, which relies on dedicated bi-hex sockets to cater for 6-22mm and 1/4-3/4in AF sizes. Though, in reality, that’s perhaps not the big advantage it first sounds because these sockets couldn’t quite match the Best Buy’s ultra-versatile flank drive hex ones in our brass nut torque test. That aside, this really is an excellent kit for the money. The sockets sport ultra-thin walls, and they’re obviously made and finished to the highest of standards. The 48-position ratchet, the handful of deep sockets, and the quantity of accessories provided also add to this product’s professional feel. Even the firm foam, which keeps everything securely in place in the case, is gloss topped for easy wipe-downs.
 
PRICE: £60.95
CONTACT: 02380 266355
WEB: www.drapertools.com
PERFORMANCE: 10/14
IS IT WORTH THE MONEY? 5/6
OVERALL SCORE: 15/20
LRM | RECOMMENDED

^ HALFORDS 125567

COMMENTS: This set has been around for so long it looks positively retro. But why bother updating something that works so well? The ratchet is perhaps the most oddball component due to its crude box spanner styling, but it’s perfectly good to use. The 44-position mechanism is plenty fine enough, and we like the sliding reverse lever’s easy-to-flick position. The sockets themselves are tough little beasts, but pretty basic. They use a standard bi-hex pattern that trails the hex and flank drive bi-hex configurations in terms of grip. But it’s way better than the too-clever-by-half spline-style drive. Unsurprisingly, the socket walls are a little on the chunky side, but we can’t complain too much about a sub £30 set that covers 3/8-13/16in and 8-19mm.
 
PRICE: £26.99
CONTACT: 08457 626 625
WEB: www.halfords.com
PERFORMANCE: 5/14
IS IT WORTH THE MONEY? 6/6
OVERALL SCORE: 11/20
LRM | BEST BUDGET BUY

^ METRINCH 0525

COMMENTS: Years ago, Metrinch kicked off the whole “one socket fits both metric and imperial sizes” scene. And, in some ways they are still masters of their game. Cutting to the chase, the sockets use a slightly more rounded flank drive hex pattern than Franklin’s Best Buy and they actually grip even more securely. From a usability point of view, Metrinch have an advantage too. All of their sockets are marked with both the imperial and metric size – an idea they patented, which is why other manufacturers can’t follow suit. So far, then, so good. So why the low score? Well, as good as this set is, it doesn’t offer a lot for the money. The sizes are limited to 10-19mm (minus 15 and 18), and 3/8-3/4in. And it’s not as if the product is exactly overflowing with accessories either.
PRICE: £57.07
CONTACT: 01604 790982
WEB: www.serenco.co.uk
PERFORMANCE: 5/14
IS IT WORTH THE MONEY? 1/6
OVERALL SCORE: 6/20



THE VERDICT:

As the years go by, and more and more older vehicles end up in breakers’ yards, the demand for imperial tools drops ever further. There will come a point, eventually, where purely imperial tooling will be practically unavailable. And the few firms that do continue with it will be able to charge what they like. So, providing it’s good enough, multi-size socketry may well be the answer. Franklin, which takes the Best Buy with its XL3826, really proves this point. The XL3826 sports one set of sockets to cater for both metric and imperial sizes, and they work incredibly well – gripping almost as securely as dedicated hex sockets. Not having to supply two full ranges of sockets has also meant that Franklin has been able to keep the price down and has splashed out on the accessories. We particularly like the 72-position ratchet.
Our other award winners, Halfords’ Best Budget Buy 125567 and Draper’s Recommended 43592, take the more traditional approach of one socket caters for one size only. The 125567 is a fantastic bargain imperial/metric set, whereas Draper’s 43592 is a high spec product that seems incredibly good value for a smidgen over £60.
 





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