Intro
Running electrical cables and plumbing pipes through walls is a fundamental part of any renovation or new build, and the neatness and speed of that work depends almost entirely on how cleanly you can cut the channels — or 'chases' — that house them. Doing it with an angle grinder and a hammer and chisel is slow, messy, and exhausting. The dust is monumental, the channels are uneven, and the risk of cutting too deep or wandering off the line is constant. A dedicated wall chaser — also called a groove cutter or chasing machine — solves all of these problems in a single, purpose-built tool. It runs two diamond cutting discs in parallel, simultaneously cutting both sides of the channel in one pass. The waste material between the cuts is then knocked out with a chisel or breaker, leaving a clean, straight, perfectly parallel channel ready for conduit or pipe. For electricians, plumbers, and renovation contractors, a wall chaser turns one of the dustiest, messiest jobs on site into a fast, controlled, and — with proper dust extraction — surprisingly clean operation.
Generalities
Selecting a wall chaser involves evaluating several technical and practical features. Motor power — 1500 watts is a common and capable rating — determines how well the machine maintains cutting speed in hard brick, concrete, and aerated block. Disc diameter, typically 125 mm for handheld chasers, sets the maximum cutting depth; paired discs can usually cut channels between 8 and 30 mm deep and up to 30 mm wide by adjusting the spacer between the discs. Speed, measured in RPM, affects cutting efficiency — 8500 RPM with diamond discs cuts quickly and cleanly through masonry. Dust management is critical: a wall chaser generates an enormous volume of fine, harmful silica dust, and a vacuum extraction port that connects to an industrial vacuum is not a luxury — it is essential for health and visibility. Soft start is a valuable safety feature that prevents the tool from jerking in your hands when the motor kicks in. DEDRA is a Polish power tool brand with a growing reputation for professional-grade tools at competitive prices, popular across European construction markets.
This review examines the DEDRA DED7918, a 1500-watt wall chaser with 125 mm discs, 8500 RPM speed, soft start, adjustable groove depth from 8 to 30 mm, vacuum adapter, and a 3-metre power cable. We will evaluate its cutting performance in brick, concrete, and block, test the dust extraction with a connected vacuum, assess the ergonomics and build quality, and identify which trades and projects this chaser is best suited for.
Description
The DED7918 is powered by a 1500-watt (approximately 2 horsepower) corded electric motor that spins a pair of 125 mm diamond cutting discs at 8,500 RPM. This combination of power and speed produces clean, fast cuts in brick, concrete block, aerated concrete, limestone, and sandstone. The cutting depth is adjustable from 8 mm to 30 mm, and the cutting width can be set up to 30 mm by adjusting the spacer between the two discs — covering the full range of channel sizes needed for standard electrical conduit (typically 20 to 25 mm diameter) and plumbing pipe (15 to 22 mm). The two diamond discs are included with the machine, so you can begin work immediately. The motor housing is made from reinforced plastic, designed to withstand the vibration and impact of daily job-site use, and the overall build reflects the tool's professional positioning.
The soft start function is a genuine practical benefit on a tool of this power. When you squeeze the trigger, the motor ramps up gradually rather than kicking in at full speed instantly. This prevents the machine from twisting in your hands on startup — important because a pair of 125 mm discs spinning up to 8,500 RPM generates significant gyroscopic force. The side handle is positioned for a secure two-handed grip that keeps both hands well away from the cutting discs, and it can be mounted on either side of the body for left or right-handed operation. The depth adjustment is a simple mechanical roller guide at the front of the base plate that controls how deep the discs penetrate, and it locks securely at the selected depth. The spindle lock button holds the arbour still for disc changes — which require the included spanner — and the process is straightforward once you are familiar with it.
In operation, the DED7918 cuts through standard red brick at a steady walking pace. The two parallel discs cut clean, straight channels with parallel walls, and the depth guide keeps the cut consistent along the full length of the chase. In harder engineering brick and dense concrete, the feed rate slows but the 1500 W motor maintains RPM without bogging — you guide the tool steadily rather than forcing it. The dust extraction port, when connected to a suitable industrial vacuum cleaner (class L or M for construction dust), captures the vast majority of the silica dust at source. This transforms the working environment from a dust cloud where you cannot see the cut line to a clean, visible operation — and, more importantly, it protects your lungs from the fine crystalline silica dust that causes silicosis. The 3-metre power cable provides reasonable mobility on site, though for larger rooms an extension lead will be needed. After cutting both sides of the channel, the waste material between the cuts is removed with a chisel, breaker, or SDS hammer with a chisel bit — a quick secondary operation.
The included accessories add value. Two diamond cutting discs come with the machine, giving you a spare pair or the ability to replace worn discs immediately. A spanner for disc changes and an adjustment tool for the disc spacing complete the kit. The 5.5 kg weight is typical for a wall chaser of this power — heavy enough to stay planted on the wall during cutting, which actually aids control, but manageable for the duration of a standard chasing job. The vacuum adapter is a standard size that fits most construction vacuum hose diameters. The tool is manufactured in Poland to DEDRA's specifications, reflecting the brand's European manufacturing base.
The DED7918 carries a 4.6 out of 5 stars rating, though from a small sample of 5 reviews — early positive feedback but not yet a large user base. It ranks #372 in Circular Saws, which reflects its niche position as a specialised chasing tool rather than a general-purpose saw. For electricians, plumbers, and renovation contractors who regularly cut wall chases, the combination of 1500 W power, dual 125 mm discs, soft start, and vacuum extraction makes this a capable professional tool at a price point well below the premium German and Swiss alternatives. It is a specialised investment that directly improves the speed, cleanliness, and quality of one of the most common — and messiest — jobs in construction and renovation.
Pros and cons
Pros
- Dual 125 mm diamond discs cut both sides of the channel simultaneously in a single pass — produces perfectly parallel, clean-edged chases ready for conduit or pipe installation.
- Soft start function prevents the tool from jerking on startup — a genuine safety benefit given the gyroscopic force of two 125 mm discs spinning at 8,500 RPM.
- Adjustable cutting depth (8 to 30 mm) and width (up to 30 mm) covers the full range of standard electrical and plumbing chase requirements.
- Integrated vacuum extraction port connects to a construction dust vacuum — captures silica dust at source, protecting both visibility during cutting and long-term respiratory health.
- Two diamond discs included — a spare pair in the box means no immediate consumable purchase needed and a backup when discs wear.
- 1500-watt motor with 8,500 RPM maintains cutting speed in hard brick and dense concrete — does not bog down under load when used at the correct feed rate.
- Reinforced plastic housing and 5.5 kg weight are built for professional job-site durability — the tool is designed for daily trade use, not occasional DIY.
Cons
- Limited review base — only 5 customer ratings at the time of writing, meaning long-term reliability and durability data for this specific model is minimal.
- At 5.5 kg, this is a heavy tool — vertical wall chasing is manageable but overhead work on ceilings is extremely fatiguing and not recommended with this weight class.
- DEDRA is less widely known than premium brands like Hilti, Makita, or Bosch — spare parts availability and service centre coverage may vary by country and region.
- Disc changes require the included spanner — unlike some premium models that offer tool-free disc changes, this adds a small amount of time to blade swaps.
- The 3-metre cable, while adequate for most rooms, means an extension lead is necessary for larger spaces or when working far from the nearest socket.
Use cases
The DEDRA DED7918 is the ideal wall chaser for professional electricians, plumbers, and renovation contractors who regularly cut channels in masonry walls for electrical conduit and plumbing pipe — it is a specialised professional tool, not a general-purpose saw or a DIY gadget.
Electrical Conduit and Cable Chasing
The primary use case. Electricians running new wiring in brick and block walls — for additional sockets, light switches, data cables, or complete rewires — can cut clean, parallel channels at the exact width and depth needed for standard 20 mm and 25 mm oval conduit. The vacuum extraction keeps the dust manageable inside finished rooms during renovation work, and the consistent depth prevents cutting too deep into the wall structure.
Plumbing Pipe Chasing
Plumbers installing new hot and cold water feeds or central heating pipework in solid walls can chase channels at the required width for 15 mm and 22 mm copper or PEX pipe. The clean, parallel cuts mean less making-good with plaster after the pipes are fitted, and the vacuum extraction prevents the fine brick dust from spreading throughout the house. The adjustable depth prevents cutting deeper than necessary into structural brickwork.
Renovation and Building Adaptation
During full property renovations, wall chasers are used extensively to modify existing electrical and plumbing layouts in solid-walled properties. The DED7918 handles the volume of chasing needed across an entire house — dozens of linear metres of channels — without overheating or losing performance. The soft start and secure side handle make this volume of work manageable, and the 1500 W motor maintains speed throughout long working days.
New Build First Fix Installation
On new construction sites with block-work walls, electricians and plumbers chase channels before plastering. The DED7918 works quickly through aerated concrete and lightweight block, and the vacuum extraction keeps the work area compliant with on-site dust control requirements. The 8 to 30 mm depth range covers the shallow chases needed in load-bearing walls where cutting depth must be minimised.
Commercial and Industrial Installation
For electricians installing conduit and cable tray systems in commercial and industrial buildings, the wall chaser handles the wall penetrations and vertical chases needed to route power and data cables. The 1500 W motor handles the harder concrete and engineering brick commonly found in commercial construction, and the consistent cutting depth ensures compliance with fire-stopping and structural requirements for wall penetrations.