Understanding Clipper Blade Numbers
Clipper blade sizes follow a numbering system where higher numbers mean shorter cuts. A #40 blade cuts to 0.25mm (surgical close), while a #3F leaves 13mm of hair or fur. This is counterintuitive for beginners, but once you learn the system it becomes second nature.
The most widely used system is the A5 detachable blade standard, originally developed by Oster and now universal across Andis, Wahl KM series, and most professional pet clippers. SUMTHIN manufactures A5 blades in all standard sizes using MIM (Metal Injection Molding) powder metallurgy for superior consistency and edge retention.
Complete Blade Size Reference Table
| Blade # | Cut Length (mm) | Cut Length (inch) | Best For |
|---|---|---|---|
| #50 | 0.2mm | 1/125" | Surgical prep, very close work |
| #40 | 0.25mm | 1/100" | Surgical prep, paw pads |
| #30 | 0.5mm | 1/50" | Close clipping, medical prep |
| #15 | 1.2mm | 3/64" | Close body work |
| #10 | 1.5mm | 1/16" | Most common grooming blade — body clips, sanitary areas |
| #9 | 2.0mm | 5/64" | Medium close body work |
| #8½ | 2.8mm | 7/64" | Medium body clips |
| #7F | 3.2mm | 1/8" | Full-tooth body clips, all-purpose |
| #7 | 3.2mm | 1/8" | Skip-tooth version — faster but rougher |
| #5F | 6.3mm | 1/4" | Leaves visible coat, popular for pets |
| #5 | 6.3mm | 1/4" | Skip-tooth version |
| #4F | 9.5mm | 3/8" | Longer pet trims |
| #4 | 9.5mm | 3/8" | Skip-tooth version |
| #3F | 13mm | 1/2" | Longest standard blade — teddy bear cuts |
| #3 | 13mm | 1/2" | Skip-tooth version |
F vs Skip-Tooth: What's the Difference?
Blades marked with "F" (Full-tooth/Finish) have closely spaced teeth that produce a smooth, even cut. Skip-tooth blades have wider-spaced teeth — they cut faster and handle matted or thick coats better, but leave a rougher finish. For most grooming work, F (finish) blades are preferred.
Hair Clipper Blade Sizes (Human / Barber)
For human hair clippers (barber/salon use), blade sizing works differently. Most professional clippers use adjustable taper blades or fixed blade sets:
| Type | Cut Length | Use |
|---|---|---|
| #000 (Triple Zero) | 0.5mm | Skin fades, bald fades |
| #00000 (5-Zero) | 0.2mm | Closest cut without shaving |
| #1 | 2.4mm | Short tapers |
| #1A | 1.2mm | Blending |
| #2 | 6.4mm | Medium tapers |
| Standard taper | 0.5–2.5mm | Adjustable range |
T-blades and U-blades used in trimmers typically cut at 0mm (zero-gap) for sharp outlines and detail work. SUMTHIN manufactures both T-blade and U-blade configurations for professional trimmers.
How to Choose the Right Blade Size
For pet grooming:
For barber/salon:
Blade Material Matters
The material your blade is made from directly affects performance, longevity, and heat:
Stainless Steel (440C): The industry standard. Hardness HRC 58-62, excellent edge retention, affordable. Works for most applications.
Ceramic Moving Blades: Stay cool during extended use — up to 75% less heat generation than steel. Edge life is approximately 5× longer than steel. Ideal for all-day grooming sessions. SUMTHIN produces 19 ceramic moving blade models.
MIM Powder Metallurgy: Allows complex blade geometries impossible with traditional machining. Superior consistency and density. SUMTHIN's A5 and D-series blades are all MIM-manufactured.
Compatibility Note
SUMTHIN blades are manufactured to the same dimensional specifications as the original equipment blades. Our A5 series fits all standard A5-compatible clippers including Andis (AGC, UltraEdge), Oster (Golden A5, Turbo A5), Wahl (KM2, KM5, KM10), LAUBE, Heiniger, and more.
For human clipper blades, SUMTHIN produces replacement blades compatible with Wahl, Andis, VGR, KEMEI, and Wmark clippers.