Hilti AG 125-13S 125 mm Angle Grinder

The Hilti AG 125-13S is a 1300 W corded angle grinder for 125 mm discs, used for cutting and grinding steel and mineral base materials. It weighs 2.5 kg, runs at 11,500 rpm no-load and carries Active Torque Control and Hilti Smart Power, which adjusts power output to suit the material being cut.

Fabrication-shop grinding and cutting with a jam-protected body

Hilti lists cutting, rough and fine grinding of metals and mineral materials, removing coatings on cement and screed, and renovating joints. A long-lasting carbon brush, a non-slip grip area and a soft-grip side handle are named as the comfort and durability features, and cutting and slitting up to 25 mm wide using two discs is possible with DC-EX 125/5 in accessories.

Active Torque Control stops the tool body from spinning if the disc jams, which is the main cause of grinder injuries. The trigger is listed as constant-on rather than dead-man type, so site rules that require a deadman switch should be checked against the AG 125-20D or the cordless AG 4D-22 instead.

Technical specifications

Permitted wheels and what to confirm before ordering

The operating instruction requires synthetic-resin-bonded, fibre-reinforced wheels with a maximum diameter of 125 mm, approved for at least 11,500 rpm and a peripheral speed of 80 m/s. Listed wheel types include abrasive cut-off wheels (maximum 2.5 mm thick), diamond cut-off wheels for mineral materials (3 mm), abrasive grinding wheels (6.4 mm) and wire brushes up to 125 mm. When cutting or slitting with abrasive cut-off wheels, use the standard guard with additional cover plate.

Specify the supply voltage and plug type for your site, and decide whether you need a dust hood for mineral cutting. For longer-duration production grinding with a deadman trigger, see the AG 125-20D; for cordless work, the AG 4D-22.

Wire brushes are listed in the 3CS, 4CS, 3SS and 4SS designations, and diamond grinding wheels for mineral surfaces are listed as DG-CW types, so the same tool can be fitted for surface preparation as well as cutting.

Hilti angle grinder range at a glance

Corded and cordless grinders listed by Hilti, with the disc size and maximum cutting depth each is built around.

Choosing between the AG 125-13S and its siblings

The AG 125-13S suits crews who need a 125 mm corded grinder for mixed metal and mineral work and who want Smart Power to moderate output as the material changes under the disc. Its 34 mm cutting depth matches the AG 125-20D and the cordless AG 4D-22, so the selection between these three is driven less by capacity than by trigger type, supply and duty pattern. Where a permit or contractor safety plan requires a deadman trigger, the constant-on switch of the AG 125-13S rules it out and the AG 125-20D is the corded alternative. Where long extension leads are impractical, such as on scaffolds or remote pipe racks, the AG 4D-22 removes the cable altogether.

If the work is mostly deep cuts in thick section or masonry, the 125 mm disc may be the limiting factor; the AG 180-D and AG 230-24D in the range table cover 42 mm and 68 mm depths at the cost of considerably more weight. For light trimming close to the body, the AG 100-D and AG 115-D are smaller and lighter.

Setting up the grinder before first use

• Match the guard to the disc: the operating instruction calls for the standard guard with additional cover plate when cutting or slitting with abrasive cut-off wheels.
• Check every wheel against the limits in the manual before fitting it, namely 125 mm maximum diameter, approval for at least 11,500 rpm and a peripheral speed of 80 m/s.
• Fit the soft-grip side handle on the side that keeps the operator’s hands clear of the disc path for the cut being made.
• Confirm the site supply voltage and plug arrangement agree with the version ordered before connecting the tool.
• For twin-disc slitting up to 25 mm wide, use the DC-EX 125/5 accessory referred to on this page rather than improvised spacers.

Care, wear parts and fault finding

Because the AG 125-13S uses a long-lasting carbon brush, brush wear is the routine service item to keep an eye on in a busy workshop; follow the operating instruction and use Hilti service for replacement. Keep the motor ventilation openings clear, since grinding dust and screed residue packed into the housing reduce cooling. If Active Torque Control repeatedly shuts the tool down, the usual causes are a disc being forced into the cut, a pinching workpiece or a wheel type unsuited to the material, so review the technique and the wheel before suspecting the tool.

Noise and vibration figures of 94 dB(A) and 5.3 m/s2 are listed in the specification table, so hearing protection and sensible limits on continuous trigger time should be part of the job method for longer grinding shifts.

Using the AG 125-13S on Omani and GCC sites

Summer work in Oman often means grinding in direct sun on steel that is already hot to the touch. Allow breaks so the operator, not only the tool, can cool down, and store abrasive wheels out of direct sun and moisture because resin-bonded discs should be kept dry. Fine desert dust and cement dust from screed removal tend to enter the housing, so blowing out the vents at the end of each shift is a sensible habit. In coastal yards around Sohar, Duqm and Muscat, salt-laden air encourages corrosion on exposed metal parts, so wipe the tool down and store it in its case rather than leaving it on open racks. For mineral cutting indoors, the dust hood mentioned under ordering should be considered together with the site’s respiratory protection rules.

Documents and quotation

Request pricing and availability for the AG 125-13S from Seven Star LLC, an independent supplier in Muscat serving Oman and the GCC. Please include the application, the supply (voltage and plug, or battery size and charger) and the quantity. The manufacturer’s multilingual operating instruction is attached for review before purchase; it is a manual rather than a datasheet. Browse more grinding and cutting tools in the Material Handling & Lifting Equipment category.