Clipper Blade Size Chart: Complete Guide to Blade Numbers, mm Lengths & Uses
A comprehensive clipper blade size chart with blade numbers (#10, #30, #40, etc.), cutting lengths in mm, and recommended uses for barbers, groomers, and pet professionals.
Choosing the right clipper blade size is critical for achieving the desired cut length — whether you're a barber, pet groomer, or livestock professional. This comprehensive blade size chart covers all standard blade numbers, their cutting lengths in millimeters, and the best applications for each.
A5 Detachable Blade Size Chart
A5 blades use an industry-standard snap-on system compatible with most professional clippers from Andis, Oster, Wahl KM series, and many others. The blade number indicates the cutting length — higher numbers mean shorter cuts.
| Blade # | Cut Length | Best For |
|---|---|---|
| #3F / #3FC | 13mm (1/2") | Longest A5 cut. Body clipping for horses, long pet trims |
| #4F / #4FC | 9.5mm (3/8") | Medium-length pet grooming, body work |
| #5F / #5FC | 6.3mm (1/4") | General pet grooming, popular all-purpose size |
| #7F / #7FC | 3.2mm (1/8") | Short pet trims, face and feet work, show grooming |
| #10 | 1.5mm (1/16") | Very short trim. Pre-surgical prep, poodle faces/feet |
| #15 | 1.2mm | Surgical prep, very close trimming |
| #30 | 0.5mm | Surgical close. Under guard combs, setting lines |
| #40 | 0.25mm | Closest cut available. Surgical prep only |
Key rule of thumb: The higher the blade number, the shorter the cut. A #40 blade cuts almost to the skin (0.25mm), while a #3F leaves 13mm of hair.
What Does "F" and "FC" Mean?
"F" stands for finish cut — blades with closely spaced teeth that leave a smooth, even finish. "FC" means finish cut as well (the terms are interchangeable across brands). Skip-tooth blades (without the F designation) have wider-spaced teeth for faster cutting through thick or matted coats, but leave a rougher finish.
Hair Clipper Blade Sizes for Barbers
Professional barber clipper blades use a different sizing system than A5 pet blades. Standard taper blades adjust from closed (approximately 0.5mm) to open (approximately 2.5mm) using the clipper's lever. For more precise lengths, barbers use numbered guide combs over a standard blade.
T-blades and U-blades are specialized trimmer blades designed for outlines, fades, and detail work. T-blades have a wider, exposed cutting edge for precise lines, while U-blades have rounded corners for safer skin contact.
Ceramic vs Steel: Does Blade Material Affect Cut Length?
No — ceramic and steel blades of the same size number cut to the same length. The difference is in performance: ceramic blades stay sharp approximately 5x longer and generate 75% less heat during operation. This makes ceramic ideal for busy salons and groomers who use their clippers all day.
How to Choose the Right Blade Size
Consider three factors when selecting a blade size:
- Desired hair/coat length: Match the blade number to your target length using the chart above.
- Coat condition: Matted or thick coats may require a shorter blade first, then a longer blade for the final pass.
- Application: Surgical prep requires #30 or #40. General pet grooming typically uses #5F or #7F. Barber fades use adjustable taper blades with guide combs.
Blade Maintenance Tips
Regardless of size, all clipper blades perform better with proper maintenance:
- Clean and oil blades after every use
- Use blade wash or spray coolant during extended sessions
- Store blades in a dry, protective case
- Sharpen or replace blades when cutting performance drops — a dull blade pulls hair and generates excess heat
At SUMTHIN, we manufacture A5 detachable blades in all standard sizes (#3F through #40) using MIM powder metallurgy for consistent hardness and edge retention. Our ceramic moving blades are available as drop-in replacements for any steel blade. Browse our full blade catalog or request a quote.