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by Peter Brett - September 2005
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Screwdriver Sophistication
Some professional jobs could not be undertaken nearly as swiftly without the safeguard of a torque control, so I suppose it was only a matter of time before somebody applied it to manual screwdrivers. Fittingly, it is Wera who have developed and marketed adjustable and fixed torque manual screwdrivers. Wera, it seems, is not content with sitting on its screwdriving laurels, progress and innovation are paramount.
Last year I tried the Rapidaptor screwdriver chuck and I found it to be one of the easiest to use and most accurate I have tried, so it comes as no surprise that the Rapidaptor chuck, with its one-handed operation is at the end, as it were, of the screwdrivers sent for review. I won&Mac226;t concentrate on the chuck therefore, but move on to the Torque Tools themselves.
Anyone familiar with the look of Wera screwdrivers might not notice anything too different with the Torque Tools. The familiar black Kraftform handles with the ergonomic grippy green bits conceal the “works” of the torque control. You really need to look closely to understand the differences, but once you do they are obvious. When I showed these tools to some jobbing builders they were sceptical to say the least.
Most of the time they would have no use for such sophistication. But as I worked along the spectrum to skilled plumbers, especially CORGI registered ones, and to mechanics working on expensive and performance cars there was a great deal more interest. Here, there is the realization that a cordless drill driver is not an option when you are fixing the innards of a boiler, or in the depths of an engine bay. Space is at a premium!
There are a couple of handle variations available in the Torque Tool range, namely the ‘standard&Mac226; Kraftform’ handle, and a pistol grip version that provides more opportunity to give things a twist. On the Kraftform handled version the adjustable torque variation is achieved by pulling back a collar on the bottom of the handle and engaging the torque control. By twisting the collar clockwise the amount of torque can be increased and similarly decreased by turning it the other way. Each 180 degree twist increases or decreases the torque and the indicator scale on the shaft of the screwdriver indicates the torque value in Nm. Wera claim an accuracy of torque reading of plus or minus 6% and each screwdriver in this range is supplied with a factory calbration certificate.
The pistol handled version is similar in operation, but the adjustment is done by removing a spanner cunningly concealed in the handle and adjusting the hexagon base of the shaft of the screwdriver.
There are a range of torque selections in the range, so the user has to select the one that is most commonly used for the tasks required. The ordinary Kraftform-handled range covers 0.3 to 1.2 Nm and 1.2 to 3 Nm. For the imperially minded Wera supply another pair of screwdrivers that cover the 2.5 to 11.5 in.lbs and 11 to 29 in.lbs range. The Kraftform pistol grip range is able to provide a torque range of 3 to 6 Nm (25 to 55 in.lbs) and is therefore able to provide a lot more twist for your money.
The review sample had a torque range of 0.3 to 1.2 Nm and I found that range enough for finely adjusting tiny screws and tightening the screws on some big 100mm brass door hinges. What is also clever about the Torque Tools is that the torque control does not work when loosening screws, so no matter how tightly the screws are in, the screwdriver will get them out again.
For most companies, these innovations would have been good enough, but Wera is not most companies and have developed a range of pre-set adjustable torque screwdrivers to fit alongside the more complicated ones reviewed above. Fixed torque screwdrivers can be particularly useful for a worker doing repetitive tasks or for fixing screws in machines where over-tightening can lead to broken or damaged screws and all the hassle and time-wasting that flows from it.
Again the range of pre-set adjustable torque screwdrivers is fairly similar to the range above. You can choose either Kraftform or Kraftform pistol grip handles and the range of torque variations is again similar. What is a major difference is that the torque of each screwdriver can be adjusted by a 7mm hex spanner via a removable cap in the top of the handle.
The user can choose or adjust an appropriate torque level and then continue to use the tool without having to vary it, knowing that it will deliver the right torque level every time it is used. To be honest, the most difficult bit of the operation I found was not the adjustment (180 degree turn equals 0.05 Nm on the 7460 version) but getting the plastic cap off the top of the handle. It fits very tight and is clearly not meant to be tampered with lightly.
But Wera have not stopped there. In addition to the above there is a series of Torx-indicator screwdrivers that are definitely not adjustable, being factory sealed at the correct torque and with tamper indicators. They are clearly aimed at high-end specialist users who demand accuracy and quality beyond the ordinary. These tools are beyond the scope of this review, but I think their development reinforces the view that Wera is a company that is always looking for new solutions and innovations. I believe that this is the best way to deal with some of the challenges coming from tool companies in the less developed countries where sometimes the bottom line is always price and quality and user satisfaction are perhaps less valued.
Independent Review by Peter Brett
Airstream Communications