8 september 2026
Comb attachment or Blade? A5-Blade cutting lengths explained
Short answer: A comb attachment clips onto a Blade (usually a #10) and leaves 3 to 25 mm of hair. A Blade cuts at a fixed length: a #10 leaves 1.5 mm, a #7F 3.2 mm, and a #4F 9.5 mm. The higher the number, the shorter the hair. For short and precise work, use a Blade; for longer coat lengths, use a comb attachment.
Last updated: August 19, 2026 — author: Team Clipr, the team behind Clipr.nl that daily tests dog clippers, Blades and comb attachments and supplies them to Dutch groomers and dog owners.
The numbering on Blades is confusing for almost everyone: a #10 is shorter than a #4F, and a #40 is almost bald. Below are all common cutting lengths in millimeters, plus when it's better to use a comb attachment and when to use a standalone Blade. All values apply to the A5 standard, the size that fits almost all professional dog clippers in the Netherlands.
In short
An A5-Blade is a universal, interchangeable Blade that fits almost all professional dog clippers, regardless of the brand.
The numbering works in reverse: higher number = shorter hair. #4F leaves 9.5 mm, #40 leaves only 0.25 mm.
The #10 (1.5 mm) is the most commonly used all-round number: good for the belly, groin, sanitary work, and as a base under a comb attachment.
Comb attachments clip on top of a #10 or #30 and provide lengths from approximately 3 to 25 mm.
F stands for Finish (full-tooth): fine teeth, even result. Skiptooth Blades have coarser teeth and should never be used on paws, face, or ears.
Short Blades (#30 and #40) heat up quickly. Check them against your wrist every few minutes.
What exactly is an A5-Blade?
An A5-Blade is a universal, interchangeable Blade that fits almost all professional dog clippers. A5 is not a brand but a form standard: the attachment (the pivot point and the drive lever) is the same for every manufacturer. This means you can use Blades from different brands on the same clipper and don't have to discard your collection of Blades when you get a new clipper. The term "A5-Blade" is also often heard in grooming salons; Blade is simply the English word for scheerkop.
An A5-Blade consists of a fixed bottom blade with teeth and a moving top blade that slides over it. The distance between these two blades determines how much hair remains; that number, the cutting length, is stamped into the metal. All A5-Blades can be found under Blades for dog clippers.
Why does a higher number mean shorter hair?
The numbering does not refer to the length that remains, but to the fineness of the teeth. The higher the number, the closer the teeth are together and the closer the blade cuts to the skin. A #40 therefore leaves 0.25 mm, a #4F 9.5 mm.
Remember it this way: the number goes up, the length goes down. So, if you want to keep a long coat, you need a LOW number — or use a comb attachment.
Which cutting length corresponds to which Blade number?
These are the standard A5 values. They are brand-independent, so a #7F from one brand cuts just as short as a #7F from another.
BladeCutting LengthTypeWhere do you use it #4F9.5 mmFinishLongest standard length; doodles, poodles, body of long-haired breeds #5F6.3 mmFinishShort summer coat that doesn't look "bald" yet #7F3.2 mmFinishClassic short summer cut; spaniels, terriers, slightly matted coat #8.52.8 mmFinishEven finishing of the body, just slightly longer than a #9 #92.0 mmFinishShort but not bare; body for thick coats #101.5 mmFinishAll-rounder: belly, groin, armpits, sanitary work, base Blade under comb attachments #151.2 mmFinishShort detail work and between paw pads #300.5 mmFinishVery short; fixed base Blade under comb attachments, paw pads #400.25 mmFinishAlmost shaving length; medical work, for experienced hands only
Are you unsure which number suits your dog's coat? The choice mainly depends on the coat type; we explain this in which dog clipper suits which coat type.
What is the difference between F-Blades and Skiptooth Blades?
The F after a number stands for Finish, also called full-tooth: all teeth are of equal length and close together. This gives an even, smooth finish without lines. For 95 percent of the work on a pet dog, an F-Blade is the right choice.
A Skiptooth Blade (often a number without F, such as #7 instead of #7F) has alternating long and short teeth. This allows it to remove thick, matted, or dirty coats faster and is less likely to get stuck. Disadvantage: the result is rougher, and the openings between the teeth are large enough to catch skin, a nipple, or an eyelid.
Rule: only use a Skiptooth Blade for rough preliminary work on the body, and never on paws, face, ears, belly, or groin. Always follow up with an F-Blade.
What is a comb attachment and how do you use it?
A comb attachment is a plastic or metal comb that you clip onto a Blade and that keeps the clipper away from the skin, so that more hair remains. The comb itself does not cut; it lifts the coat and only determines the height.
Important: a comb attachment only works well on a short base Blade, usually a #10 (1.5 mm) or a #30 (0.5 mm). If you put a comb attachment on a #7F, the blade cuts too far from the skin, resulting in an uneven, streaky finish. Always check which base Blade the manufacturer prescribes.
Comb attachmentResulting lengthTypical result 3 mm± 3 mmShort and neat, slightly longer than a #9 6 mm± 6 mmShort, even summer coat; comparable to a #5F 9 mm± 9 mmNeat short cut, coat color still shows well 13 mm± 13 mmStandard length for doodles and poodles that should not be bald 16 mm± 16 mmVisibly woolly; maintains the typical doodle look 19 mm± 19 mmLong; suitable for evening out rather than shortening 22 mm± 22 mmVery long, requires a fully combed coat 25 mm± 25 mmLongest common size, only on tangle-free and dry coat
The Clipr comb attachment set (9-piece) covers this entire range from short to long and fits the A5-Blade.
Comb attachment or Blade: what do you choose when?
CriterionComb attachmentStandalone Blade Length range± 3–25 mm0.25–9.5 mm AccuracyReasonable; can slipExact and repeatable SpeedSlower, more repetitionFaster, one pass is enough Behavior with tanglesGlides over or gets stuckCuts through or clearly stops PurchaseInexpensive, entire set at onceMore expensive per piece LifespanPlastic wears and bendsYears, blades are sharpenable Detail work (paws, face)UnsuitableNecessary
Choose a comb attachment if you want coat lengths above 9.5 mm, if you are maintaining a doodle or poodle, or if you want to start affordably without immediately buying five Blades. Choose a Blade if you work short, want exact repeatability, groom many dogs per week, or perform detail work on paws, ears, and muzzle. What best suits your situation can be determined using the selection guide.
Which set should a beginner buy?
For most dog owners who groom at home, this combination is sufficient:
A #10 (1.5 mm) as a base Blade: belly, groin, armpits, sanitary work, and holder for your comb attachments.
A #7F (3.2 mm) if you regularly want a short summer cut without a comb attachment.
A comb attachment set for all lengths above that.
If you have a dog with a long, curly coat, you can skip the #7F and directly add comb attachments to your #10.
Common mistakes with Blades and comb attachments
Keeping the Blade on the skin for too long. Short Blades (#30 and #40) become hot within minutes and can cause burns and bald spots. Hold the Blade against the inside of your wrist every two to three minutes. If it feels uncomfortably warm, it's too hot for the dog. Use cooling spray or switch to a second Blade.
Using a comb attachment on a dirty or matted coat. The comb will slip and pull on tangles. First, wash and dry the coat completely; see the step-by-step guide for dog grooming.
Using Skiptooth on paws or face. The large tooth openings can catch skin.
Continuing to work with a dull Blade. A dull blade pulls hairs instead of cutting them and causes streaks. When to sharpen or replace them is explained in replacing clipper blades.
The wrong base Blade under a comb attachment. Always a #10 or #30, unless the manufacturer specifies otherwise.
Not sure which number suits your dog? View the range of Blades or go through the selection guide.
Frequently asked questions
Which Blade is most commonly used for dogs?
The #10 with a cutting length of 1.5 mm is the most commonly used A5-Blade. It is short enough for the belly, groin, armpits, and sanitary grooming, and it is the standard base Blade onto which you clip comb attachments. Anyone buying only one Blade will almost always choose the #10 in practice.
How many mm does a #7F Blade leave?
A #7F leaves 3.2 mm of hair. This is the classic short summer cut: clearly shorter than the natural coat, but not bare. The F means Finish or full-tooth, so fine, even teeth. For a bit more length, choose a #5F (6.3 mm), for shorter, a #9 (2.0 mm).
Can I put a comb attachment on any Blade?
No. A comb attachment should be used on a short base Blade, usually a #10 (1.5 mm) or a #30 (0.5 mm). On a longer Blade like a #7F, the blade is too far from the skin, resulting in a streaky and uneven finish. Always check the comb attachment manufacturer's instructions.
What is the difference between a #10 and a #10 with a comb attachment?
A standalone #10 leaves 1.5 mm of hair. If you put a 13 mm comb attachment on it, approximately 13 mm will remain: the comb keeps the clipper further from the skin. The Blade cuts in both cases; the comb attachment only determines the height at which this happens.
