Executive Hire News › Archives › November 2008 › Executive Report : Hammering away

Executive Report : Hammering away

Phil Mist, EHN's Power Tools Specialist, assesses Hilti's newly launched hammers, featuring technology designed to enhance operator safety.

It is amazing how much power and how many features power tool manufacturers can squeeze into new models. This is particularly true of rotary hammer drills and rotary demolition hammers, and today’s machines can work harder, faster, offer more power with less noise, have lower vibration emissions and give more protection to their operators.

Hilti has just announced two new hammer drills, one of which is set to replace an existing model, while the other is to plug what was seen as a gap in the manufacturer’s range. The TE50-AVR and TE 60-ATC look similar in appearance but are decidedly different in size and performance. The former is in the 5-6kg rotary hammer drill category and can also be used for light chiselling and breaking, whilst the TE60-ATC is a 7kg demolition hammer that can also drill holes in hard concrete.

Low vibration levels

The TE50-AVR has both rotation stop and hammer stop, and is powered by a 1,050watt motor. It incorporates Hilti’s Active Vibration Reduction (AVR) system, yet still has a claimed single impact energy rating of 5.2J. The company claims that, because of its low-vibration feature, the machine can drill up to 100% more holes (of up to 20mm in diameter) than the existing TE56-ATC before the operator reaches the stipulated ELV (exposure limit value). The actual vibration figures of the tool when measured according to EN60745 are 11.4m/s2 whilst hammer drilling and 8.1m/s2 when chiselling. Both figures are a third less than those of the TE56-ATC, and this means the TE50-AVR can be used for double the amount of time. The no-load speed of the tool is 565rpm and it achieves an impressive 3,180 blows/minute. Constant speed electronics enable it to carry on working at optimum level even when being abused by the operator. Whilst I did not actually check the speed and impact rate during testing, I drilled holes of varying diameters into hard concrete in what certainly seemed double-quick time. The recommended drilling range is only 14-25mm, but it can obviously drill much larger holes. Again, the maximum recommended hammer core drilling size is only 50mm, but the machine is capable of more, as it will doubtless be expected to achieve on the typical construction site.

The quick-release SDS Max tool holder is simply pulled backwards to release the drill bit or chisel, and a low-vibration rubber side handle can be fixed in any position. A service light indicates when maintenance is needed and the rear ‘D’ shaped handle ‘floats’ to reduce vibration. The TE50-AVR is compact, weighs 5.8kg, and is extremely well balanced. It is claimed to emit noise levels of 104dB(A) sound power and 93dB(A) sound pressure.

Astonishing figures

The other new machine is the TE60-ATC combi hammer, which weighs 7.8kg. It looks huge when placed alongside the smaller machine. The on/off switch can be locked on when the machine is being used for chiselling and it has a single energy blow rating of 7J. Powered by a 1,200watt motor, it offers speeds of 480 and 700rpm (no load). When drilling, the quoted vibration figures are 9m/s2 and only 8.5m/s2 when chiselling. These are astonishing figures for such a powerful machine, and are due to Hilti’s AVR system.

The TE60-ATC’s performance can be attributed to not only its 7J impact rating, but also to its hammer speed of 2,785bpm. A recommended drilling range of 18-30mm using SDS Max drill bits looks on the modest side, but will doubtless again be exceeded on a regular basis. At the touch of a button, impact power can be halved for medium to heavy work on brittle materials. The machine has Hilti’s Active Torque Control (ATC), a safety feature which is often misunderstood by operators, since it usually cannot be felt when it activates. It only operates when the user exceeds the machine’s capabilities and might place themselves at risk. Hilti technicians believe that the ATC will cut in on average five times in a working day. This important feature can prevent injuries, especially if an operator uses a machine one-handed, and the system, therefore, is greatly superior to a conventional mechanical clutch.

The noise emissions of the TE60-ATC might seem a little high at 110dB(A) sound power and 99dB(A) sound pressure, but are in line with industry norms. It is also worth remembering that most tools of this type are used outdoors, where noise is not quite such an issue.

The selection of a particular brand of rotary demolition hammer is very much a personal choice. Virtually all the models available in the UK will drill concrete reasonably well, some will work very well, and a few machines are exceptional. Most operators will make their selection according to their past experience, but an additional consideration for the hire industry is long-term reliability. EHN’s hands-on assessments, revealing though they may be, can never replace long-term trials carried out over weeks or, even, months. However, Hilti’s additional benefits of its Lifetime Manufacturer’s Warranty, Lifetime Repair Cost Limit, and its Two-year ‘No Cost’ repair system would seem to provide many of the answers to users, as well as hire company buyers, and to help offset the premium price that has to be paid for any Hilti tool.

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www.hilti.co.uk