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Comparison Stark RH 920 Q Profi vs Stark RH 850 Profi

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Stark RH 920 Q Profi
Stark RH 850 Profi
Stark RH 920 Q ProfiStark RH 850 Profi
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Operating modes
hammer drilling
drilling only
chiselling (demolition hammer)
hammer drilling
drilling only
chiselling (demolition hammer)
Specs
Power consumption920 W850 W
Impact energy2.7 J2.7 J
Number of thrusts5500 bpm5500 bpm
Rotation speed1300 rpm1300 rpm
Reversebrushbrush
Motor locationhorizontalhorizontal
Chuck
Chuck type
SDS+
keyless
SDS+
 
Quick chuck change
Wood drilling max. 30 mm30 mm
Metal drilling max. 13 mm13 mm
Concrete drilling max. 26 mm26 mm
Features
Functions
power button lock
power button lock
General
Power sourcemains (230 V)mains (230 V)
In box
additional handle
depth gauge
chisel x2
drill 3 pcs
case (bag)
additional handle
depth gauge
chisel x2
drill 3 pcs
case (bag)
Power cord length3 m3 m
Weight2.8 kg2.8 kg
Added to E-Catalogfebruary 2019february 2019

Power consumption

Rated power consumed by the rotary hammer during operation. Usually, the maximum power consumption in normal operation is taken as the nominal power.

In general, the higher this indicator, the heavier and more performant the rotary hammer is, the more advanced its performance usually turns out to be. On the other hand, the electricity consumption of such tools is high. In addition, note that with the same power consumption, the actual set of individual characteristics for different tools may be different. For example, frequency and impact energy are inversely related, and for the same power input, higher frequency usually means less individual impact energy. So, according to this parameter, it is worth evaluating only the overall level of the instrument; for accurate selection for specific tasks, you need to pay attention to more specific characteristics.

Also note that power consumption data can be useful for some tasks related to catering — for example, if a construction site is powered by an autonomous generator and you need to estimate the load on this energy source.

Chuck type

The type of cartridge used in a rotary hammer to hold a working tool.

SD+. Abbreviation for it. "Steck-Dreh-Sitzt" — "insert-turn-fixed." Today's most common rotary hammer chuck, used in low and medium power models. It has a 10mm diameter shank with 4 slots and accepts tools from 4 to 26mm in diameter and 110mm to 1000mm in length. The advantages of SDS + are the reliability of fastening and convenience when changing tools — it does not require additional devices such as keys. The main drawback is the significant beating of the tool during rotation, due to which such a cartridge is very poorly suitable for drilling.

SDS Max. Modification of the SDS + cartridge (see above), intended for use in powerful professional models. It has a shank diameter of 18 mm and allows the use of tools with a diameter of up to 55 mm; otherwise similar to SDS+.

SDS-Quick. A variation of the SDS cartridge (see above), in the shank under which protrusions are used instead of grooves. It is also possible to install tools with 1/4" hex shanks in such a chuck. The most common tool diameter for SDS-Quick is 4-10 mm. This chuck is used relatively rarely.

Quick release. Chuck for holding drills and other tools used in drilling holes. The design is similar to those used in electric drills — it has 3 cams, it is designed for a too...l with a cylindrical shank without grooves, and hand force is enough to install / remove the tool. Such a cartridge is devoid of the main drawback of SDS — beats during rotation; this allows you to use the rotary hammer for drilling with good quality. On the other hand, it is much worse for chiselling than SDS. Therefore, keyless chucks are usually supplied as an accessory and are installed instead of the standard SDS chuck.

— Key. The presence of a special key cartridge in the delivery set of the rotary hammer, usually in addition to the standard SDS (see above). In terms of mounting design, this chuck is similar to the keyless chuck (see above) and is also designed for use in drilling. Its main difference lies in the method of installing / removing the tool: you can’t do this with your bare hands, you must use a special key to compress / unclench the cams. Such a system is somewhat more reliable than a quick-clamping system, but much less convenient: changing a tool takes a lot of time, and the key can be lost.

Quick chuck change

Possibility of quick replacement of the perforator chuck — usually from a regular SDS to a quick-clamping one (for more details, see "Chuck type"). Such replacement is carried out in a few seconds and does not require additional tools.
Stark RH 920 Q Profi often compared
Stark RH 850 Profi often compared