In Brief.

These are special purpose machines that are designed and manufactured for specific engineering applications. They are all powerful low revving machines designed for very high torque levels. Some of their applications include steel fabrication workshops and roofing work, especially for installing batten screws. They are also often used for mixing liquids in place of specific electric stirring tools.

Interestingly, two machines stood out from the others: one the most expensive, one the least expensive. The least expensive machine, the TradeTools Direct TTD800D, is a powerful & robust machine at an unbelievably low price. The most expensive machine being the Metabo BE622SLR stood out for its quality, comfort, safety plus some excellent innovations explained later in this article. Hitachi and Bosch have always provided excellent machines in terms of quality, price and proven durability. We also tested a tried and proven Makita model that offers something a little different from all of the others as it was easier to engage forward & reverse.

The Methods Of Reverse Selection.

We have included the methods of reversing for each of these drills on our summary table at the beginning of each separate tool review. This may be an important consideration if the drill is frequently used for reversing under load such as in removing batten screws. There are two methods of selecting reverse; both do the same thing i.e. polarity is reversed so that the motor spins backwards. Some machines change the polarity at the armature brushes. Others use an internal switch that is mainly located on or near the trigger. Changing polarity at the brushes does not really affect the amount of motor torque that the drill has whilst in reverse. Switching polarity elsewhere involves losses of up to 30% of torque when the machine is in reverse. If power in reverse in an important issue choose a machine that uses the brush reversal method. Switching into reverse by brush reversal is slightly more awkward and usually involves using both hands. Switching to reverse at the trigger can often be done quickly with the trigger finger without removing the drill from the work.

What We Did.

After performing our usual visual checks, we made note of any accessories that were included in the purchase price. We then recorded our comments about the overall finish and manufacturing quality. At the outset, we decided to use all of these machines in applications as close as possible to their intended use. We initially tried them all out by screwing some large batten screws, approximately 150mm long, into a piece of very old hardwood. They all happily performed this task and consequently we had no hesitation in stating that all of these machines would install batten screws all day long. But that did not tell us all we needed to know about the machine’s capabilities so we then installed a few large auger & steel drill bits and really went to work! Believe me, when you use these machines with a 24mm auger bit you’ had better really hang on! We were genuinely amazed (and impressed) by the huge torque levels that these powerful drills actually have. We drilled several holes, using all of the machines, in both timber and steel and were then able to comment further on each machine’s comfort, power, quality, and overall performance.The table below comprise a summary showing the basic characteristics of each machine reviewed. We separated each machine into either Trade Duty or Industrial Duty. Our pick of the Industrial Duty machines is the Metabo BE622SLR. This is mainly due to its obvious high quality, overall comfort and its excellent power to weight ratio.

Our pick of the Trade Duty models has to be the TradeTools Direct TTD 800D. Its incredibly low price – almost one quarter of the cost of the Metabo BE622SLR – makes it really a stand out buy!