How to Choose the Right Angle Grinder (100mm vs 125mm)

Angle grinders look similar at a glance, but the wheel size changes how the tool behaves on site. A 100mm grinder feels light and precise, while a 125mm grinder offers more reach and faster removal. Use the points below to pick the size that matches the work you do most.

Cutting depth and reach

Wheel diameter is the most obvious difference, and it shows up in cut depth.

• 100mm wheels are compact and easy to control, but you lose a few millimeters of depth on thicker stock.
• 125mm wheels reach deeper and clear larger profiles in fewer passes.

If you regularly cut angle iron, thicker rebar, or masonry, the 125mm size gives you breathing room. For tile trims, thin sheet metal, or detailed finish work, the 100mm grinder keeps cuts cleaner.

Power and torque

Larger wheels add load. Most 125mm grinders ship with a higher wattage motor to keep the wheel speed stable under pressure. That extra torque helps when:

• grinding down welds,
• cutting multiple bars in one setup,
• or working with dense materials like granite.

If you need quick touch-ups and light deburring, the 100mm platform is easier on your wrist and still gets the job done.

Control and fatigue

Compact grinders are easier to maneuver in tight corners, overhead work, and extended sessions. The lighter head reduces fatigue and gives better visibility of the cut line. The larger housing of a 125mm grinder is steady and powerful, but it can feel bulky for detail work.

Ask yourself where the tool will live most of the time:

• Shop bench or fabrication bay: 125mm is comfortable for repeat work.
• On-ladder or inside cabinets: 100mm is safer and more precise.

Wheel availability and cost

Both sizes are widely stocked, but 100mm consumables are often slightly cheaper. If your team goes through a lot of cutting wheels, that adds up. On the other hand, 125mm wheels can last longer because the usable surface area is larger.

Quick decision guide

• Choose 100mm if you prioritize control, lighter weight, and detail work.
• Choose 125mm if you need more cutting depth and faster material removal.
• Own both if you switch between finishing work and heavy cutting throughout the week.