100T vs 120T Aluminium Saw Blade — Which Tooth Count Do You Need?

Buying an aluminium cutting saw blade and stuck between 100T and 120T? This is one of the most common questions we get from buyers, and the answer isn’t “more teeth is always better.” The right tooth count depends on what you’re cutting, how thick the material is, and what finish quality you need.

Why Tooth Count Matters for Aluminium

Unlike wood, where tooth count mainly affects cut speed vs. finish, aluminium cutting is more sensitive. Aluminium is soft and ductile — it tends to stick to blade teeth under heat. Too few teeth and each tooth takes a bigger bite, generating more heat. Too many teeth and the chip gullets are too small to clear aluminium chips, causing loading.

The 100T vs 120T choice is essentially a balance between cutting efficiency and surface finish.

100T: The General-Purpose Workhorse

Best for:

• Aluminium profiles with wall thickness 2-4mm

• Solid aluminium bars and rods

• Thicker extrusions where chip volume is high

• Production cutting where speed matters

Why it works:
100 teeth on a 250-300mm blade means larger gullet space between teeth. Aluminium chips — which are curly and stringy — have room to exit the cut without packing. Less chip packing means less heat, less loading, and longer blade life.

Trade-off:
The cut surface on thin-wall profiles may show very faint tooth marks. Not a problem for structural applications, but may require a quick deburr for visible surfaces.

120T: The Precision Finish Specialist

Best for:

• Thin-wall aluminium profiles (0.8-2mm wall thickness)

• Window and door extrusions where visible surface quality matters

• Aluminium tubes and hollow sections

• Applications requiring zero post-cut finishing

Why it works:
120 teeth means each tooth takes a smaller, finer bite. The cut surface comes out smoother — often burr-free on both top and bottom edges. For window and door manufacturers, this eliminates the deburring step, saving time and labor.

Trade-off:
Smaller gullets mean chips must exit faster. If you’re cutting thick solid aluminium, chips can pack and cause loading. 120T is not ideal for thick-wall or solid bar cutting.

Quick Selection Guide

Diameter Also Affects the Choice

The same tooth count behaves differently at different diameters:

• 250mm 100T: Medium tooth pitch, good for general profiles

• 250mm 120T: Fine pitch, excellent for thin-window profiles

• 300mm 100T: Slightly coarser pitch (same teeth, bigger circumference), good for thicker material

• 300mm 120T: Medium-fine pitch, the most versatile aluminium blade

• 350/400mm 120T: Coarser pitch despite 120 teeth (large circumference), designed for large profiles

If you’re cutting a mix of thin and thick material and want one blade, 300mm 120T is the most versatile choice.

Don’t Forget Lubrication

Regardless of tooth count, aluminium cutting requires lubrication. Use cutting wax or aluminium-specific cutting fluid. This reduces friction heat by up to 50%, prevents aluminium from welding to tooth tips, and significantly extends blade life. Even the best 120T blade will load without lubrication.

The Bottom Line

Choose 100T when you need chip clearance and cutting speed on thicker material. Choose 120T when you need burr-free finishes on thin-wall profiles. If you cut a range of aluminium materials, stock both — using the wrong tooth count costs more in blade damage and rework than buying a second blade.

AOMJNG offers both 100T and 120T TP-geometry aluminium cutting blades in 250mm, 300mm, 350mm, and 400mm diameters, with OEM/ODM customization available.