A hard-wearing turbo rim diamond blade for general masonry work on site. The SMI7 cuts roof tiles, concrete paving, blockwork and occasional light steel. Available in sizes from 115mm up to 350mm diameter to suit angle grinders and disc cutters.
Size
Price
QTY
115mm x 22mm
£4.90£5.88
125mm x 22mm
£5.90£7.08
230mm x 22mm
£14.90£17.88
300mm x 20mm
£27.90£33.48
350mm x 20mm
£37.90£45.48
350mm x 25mm
£37.90£45.48
The Dart Red Ten SMI7 multi purpose blade is a solid workhorse for tradespeople who need a reliable diamond blade without paying over the odds for something they’ll get through on site. It’s designed around a turbo rim segment — that segmented, wavy edge that pulls material out of the cut faster and keeps the blade cooler as it works. The 10mm segment depth gives you decent working life before you’re cutting on the core, which matters when you’re running through roof tiles all day.
Masonry is where this blade earns its keep. Concrete paving, blockwork, roof tiles — anything that’s hard and abrasive but not unpredictably dense. The turbo rim design means cutting speed is noticeably better than a plain segmented blade of similar spec, and the 22mm bore fits standard angle grinders straight out of the box on the smaller sizes. The 300mm and 350mm versions step down to a 20mm bore (with one 350mm option at 25mm) to suit the larger disc cutters you’d be using at that diameter.
Where the SMI7 Multi Purpose Blade Gets Used
This is a blade for general site conditions. Roofers cutting plain and interlocking tiles, groundworkers trimming paving slabs, bricklayers cutting blocks to fit awkward corners. The 115mm and 125mm sizes suit smaller angle grinders for tight access work, while the 230mm is the standard disc cutter size used for the heavier cutting on slabs and kerbs. At 350mm you’re looking at large floor saws and cut-off saws for volume work.
Light Steel Cutting
The SMI7 can be used on light steel, but be straight with yourself about what that means. Thin sheet, angle iron, the occasional bolt. Not structural sections or continuous steel cutting runs. Diamond blades are not angle grinder cutting discs, and using this blade regularly on steel will wear it out fast and produce results that’ll disappoint. Treat the steel capability as a convenience for occasional use, not a primary function.
Available in six sizes, the Dart Red Ten SMI7 multi purpose blade is priced sensibly for a trade product that performs well across the most common masonry cutting jobs on site.
Pro Tip: Always uncoil any water supply hose fully before wet cutting, and check the blade is spinning in the correct direction before you start — a diamond blade run backwards will strip the segment bond faster than the material ever will.
The SMI7 is used across roofing, groundworks, and general building trades wherever masonry cutting is part of the job. Roofers reach for the smaller 115mm and 125mm sizes to cut plain tiles, concrete interlocking tiles, and fibre cement slates to fit verges and hips. Groundworkers use the 230mm version for paving slabs and edging stones, while the 300mm and 350mm sizes are at home on larger disc cutters cutting kerb stones, dense concrete blocks, and copings. It also handles the odd bit of light steel when you need it to, though sparingly.
Best For
Roof tiles (plain and interlocking)
Concrete paving slabs
Blockwork and brickwork
Kerb stones and copings
Occasional light steel cutting
Compatible With
115mm angle grinders (22mm bore)
125mm angle grinders (22mm bore)
230mm disc cutters (22mm bore)
300mm disc cutters (20mm bore)
350mm floor saws and cut-off saws (20mm or 25mm bore)
Key Specifications
Turbo rim segment design
10mm segment depth
Sizes: 115mm, 125mm, 230mm, 300mm, 350mm
Bore sizes: 22mm, 20mm, 25mm depending on size
General purpose masonry rating
Not suitable for: Not suitable for continuous or heavy steel cutting — occasional light use only. Not designed for reinforced concrete cutting where embedded rebar is a regular feature of the cut.
Fit the blade to the correct size machine, making sure the bore matches and the blade is seated flat against the flange with the arrow on the blade running in the same direction as disc rotation. Tighten the retaining nut firmly but do not overtighten.
Let the blade do the work — applying excessive downward pressure on a diamond blade slows it down and builds heat rather than improving cut speed. A steady, consistent feed rate through the material will give a cleaner cut and extend blade life. For thicker materials, making a shallow scoring pass first before cutting to full depth reduces the chance of the blade wandering.
Check the blade size and bore match your machine before fitting
Fit the blade with the rotation arrow aligned to the direction your machine runs
Tighten the retaining nut securely and check the blade runs true before cutting
Mark your cut line clearly on the material
Start the machine and allow it to reach full speed before contacting the material
Feed steadily through the material without forcing the blade
Allow the blade to cool between extended cuts — do not plunge it into water while hot
Can the SMI7 be used to cut steel regularly?
Not really. The SMI7 can handle occasional light steel cutting, thin sheet or angle iron for example, but it is not a metal cutting blade. Using it continuously on steel will wear the diamond segment rapidly and the results will be poor. For regular steel cutting, use a dedicated metal cutting disc.
Which size SMI7 blade fits a standard 9-inch disc cutter?
A 230mm blade with a 22mm bore fits the most common 9-inch disc cutters used on site. Check your machine's arbor size before ordering, as some models use adaptors for different bore sizes.
Does the turbo rim design make a noticeable difference to cutting speed?
Yes, on abrasive materials like concrete paving and roof tiles it makes a real difference compared to a plain segmented blade. The turbo profile clears debris from the cut more efficiently, which reduces drag and keeps cutting speed up. It also helps manage heat build-up during extended use.
The SMI7 uses a sintered diamond segment bonded to a steel core with a turbo-profiled rim. The 10mm segment height provides good usable life on abrasive masonry materials. The turbo rim geometry creates a faster cutting action and improved debris clearance compared to a standard segmented rim. Bore sizes vary across the range to suit the standard spindle sizes of grinders and disc cutters at each diameter.
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