Carpet knives for professionals

Handle types: carpet knife, cutter knife, safety knife, scalpel

There are many names for cutter knives, carpet knives and related knives. Here you can see at a glance how the four types differ and who mainly uses them. Which handle suits you best, however, always depends on your specific application. We are happy to advise you on the choice.

Handle typeCarpet knives

• Trapezoid or hook blade
• Sturdy metal handle
• For heavy work
• Who: floor layers, roofers, drywall fitters

Handle typeCutter knife

• Snap-off blade, usually 9 or 18 mm wide
• Blade up to 8 cm long
• Who: tradespeople, home improvers, DIY

Handle typeSafety knife

• Protection against cuts
• Automatic blade retraction
• Protects the goods when opening
• Who: retail, logistics, production, trades, industry

Handle typeScalpel

• Craft knives and deburring tools
• For precision work
• Who: plastics processing, model making, DIY

Carpet knife or cutter knife?

Some people also call a cutter knife with a snap-off blade a carpet knife. In our classification, a carpet knife is always fitted with a trapezoid blade or hook blade. Snap-off blades break off uncontrollably under excessive lateral forces and are therefore not suitable for heavy cutting work. The German dictionary Duden describes a carpet knife as a knife with a replaceable blade.

Other names for this type of knife are trapezoid blade knife, carton knife, parcel knife, box opener, utility knife or – with blade retraction – safety knife. Which cutter knife suits your work is shown in the cutter knife guide (in German).

Carpet knife with a hook blade or a trapezoid blade?

The two main shapes of the carpet knife blade are the trapezoid blade and the hook blade. Both fit the same handle as long as the blade holder matches – so you can switch depending on the task.

Carpet knivesTrapezoid blade

• Straight cuts, also along a cutting ruler
• Double-seam cut with a new blade
• Scoring wallpaper and skirting boards
• Cardboard, roofing felt, film and paper on rolls

Carpet knivesHook blade

• Gets under the laid carpet
• Pull cut, fast and safe
• Removing old carpet, relief cuts at corners
• Cutting floor coverings to size

Only in a cutter knifeSnap-off blade

• With predetermined breaking points, breaks off under high lateral forces
• Not for carpet knives
• For wallpaper, film, paper, foam

On requestCeramic safety blade

• Extra high safety
• On request only, the handle has to be modified beforehand

The Tajima hook blade (K017) fits the Tajima VRex 102 carpet knife. Which hook blade or trapezoid blade fits your carpet knife is shown by the blade finder in the blade hub (in German).

Carpet knife trapezoid blade: shape, fit, choice

The trapezoid blade is the standard blade in a carpet knife. It has two cutting edges, so it can be used twice: when one side is dull, turn the blade over. Trapezoid blades are not standardised. Whether a blade fits depends on how the handle holds it: most manufacturers hold the blade at the notches on the blade back, but not all of them.

Fit: which blade fits your handle?

Trapezoid blades look alike – but they do not fit every handle. There is no standard for the hole pattern. The blade carrier holds the blade at notches in the blade back or at large holes in the middle. These are exactly what has to match the handle.

Choose a quality

K011Basic

• Fits almost all knives
• Brand: Sheffield (UK)

K015Professional

• Black = extra sharp
• Brand: Tajima
• Our best seller

K014Premium

• Hardened with tungsten carbide
• Up to five times longer lasting
• Brand: Stanley

K013Rounded tips

• A little more safety
• Brand: Stanley

Carpet knife with a snap-off blade?

Some people look for a carpet knife with a snap-off blade. There is no such thing: a snap-off blade has predetermined breaking points and breaks off uncontrollably under high lateral forces, which is why it belongs in a cutter knife. For heavy cuts, use a trapezoid blade or hook blade. The section Carpet knife or cutter knife? shows the comparison; you will find all snap-off blades under cutter knife snap-off blades (in German).

All trapezoid blades at a glance: trapezoid blades and hook blades in the blade hub (in German).

Cutting carpet with a carpet knife

A carpet knife is called a carpet knife because this type of knife is best suited to cutting carpet. Cutting carpet takes a lot of force – hence a sturdy metal handle and a blade without predetermined breaking points. Here is how to proceed and which carpet knife blade is used for each step:

1. 1

   Scoring wallpaper so that it does not tear when the skirting boards are removed.

   Trapezoid blade
2. 2

   Removing old carpet. The hook blade gets under the carpet, and a pull cut slices through it quickly and safely.

   Hook blade
3. 3

   Relief cuts at the corners when the new carpet is laid.

   Hook blade
4. 4

   Trimming the overhang. Press the carpet into the corner with the blunt back of the blade, then cut.

   Hook blade
5. 5

   Double-seam cut along a stable cutting ruler.

   Trapezoid blade
6. 6

   Scoring skirting boards, finally trimming with the hook blade.

   Trapezoid blade, then hook blade

The thicker the carpet, the more force the cut takes. For thick carpet, therefore, use a carpet knife with a metal handle and a fresh blade.

Carpet knives for floor layers, roofers and drywall fitters

Carpet knives are tradespeople’s knives. Which blade and which handle fit depends on the material to be cut:

Carpet knife recommendation: which model for which job?

We specialise in safety knives, which is why we carry only a few carpet knives that we can recommend without reservation in terms of quality. This is how to place the models:

We are happy to clarify which carpet knife suits your work in a conversation: 0211 – 97174619.

What to look for when buying a carpet knife

Robustness

The handle should be made of metal, and so should the blade holder inside the handle – only then does the blade sit securely under heavy force. If the carpet knife has a slider to pull the blade back into the housing after the cut, that should be made of metal too.

There are big differences in robustness: from plastic that breaks quickly through thin sheet metal to sturdy aluminium. A metal handle survives a fall and cuts made with a lot of force. It also hardly wears. This matters at the front, because the housing constantly rubs over the material being cut while the blade is extended. Simple plastic wears down quickly here – at some point the blade protrudes even when retracted, which can lead to serious injuries. A soft grip is not necessary; it is more a matter of taste.

In shortMetal, metal, metal.

Ergonomics

The carpet knife should sit well in the hand so that you can work for a long time without fatigue. A grippy surface prevents it from slipping out of your hand during forceful cuts. If you like a soft grip, it should be where you hold the knife – in our experience, however, it is not a must for a secure hold.

With a professional carpet knife, the blade change works without a screwdriver, simply and quickly. Almost all high-quality carpet knives have space in the handle for spare blades (internal blade magazine).

In shortNon-slip and fatigue-free.

Blade quality

The quality of the carpet knife blade is almost the most important point. It should not only be sharp but also stay sharp for a long time, that is, have a long edge life. Unfortunately, manufacturers do not publish figures for this. We go into detail in our blade test (in German).

Also make sure that the blade fits your carpet knife, that is, that the hole pattern matches the blade holder. Most manufacturers use the notches on the blade back for locking – but not all of them.

In shortEdge life = how long the blade stays sharp.

Carpet knife blades

Trapezoid blades and hook blades come in different qualities in terms of sharpness and edge life. You will find a selection above, under the matching replacement blades; all blades are in the blade hub (in German).

Carpet knife blade | material

Carpet knife blade | changing

When the carpet knife blade becomes dull, it has to be changed. This is possible with almost all carpet knives, and with high-quality ones also without a screwdriver and much faster. If one side of the blade is dull, turn it over first. Only when the second side is dull as well do you fit a new blade. Snap-off blades belong in a cutter knife, not in a carpet knife – use only trapezoid blades or hook blades whose hole pattern matches your carpet knife. Dispose of old, dull blades safely, ideally in a collection box.

Safety carpet knives

In the past, the blade of a carpet knife was fixed in the cutting position and could not be retracted into the handle. For several decades, versions with automatic blade retraction have become established in the workplace: the blade is connected to the housing by one or more springs and snaps back after the cut to prevent cuts. As part of accident prevention, the German statutory accident insurance bodies recommend using at least this kind of safety knife.

Among tradespeople, besides the fixed blade, the manually retractable version is common, in which the trapezoid or hook blade can usually be adjusted to three cutting depths. These knives are often also called tradesman’s knives.

Carpet knife | Wiki

Frequently asked questions – FAQ

What is a carpet knife?

A carpet knife is a work knife with a replaceable trapezoid or hook blade and usually a sturdy metal handle. It is intended for heavy cutting work where a snap-off blade would break.

Which knife is best for cutting carpet?

A carpet knife with a trapezoid or hook blade is sturdier than a cutter knife with a snap-off blade. Cutting carpet takes a lot of force; hook blades are mostly used here.

Which blade fits my carpet knife?

That depends on how the handle holds the blade, because trapezoid blades are not standardised. Most manufacturers hold the blade at the notches on the blade back. Which blade fits which handle is shown by the blade finder (in German).

Is there a carpet knife with a snap-off blade?

No. Snap-off blades have predetermined breaking points and belong in a cutter knife. Carpet knives take trapezoid blades or hook blades.

What else is a carpet knife called?

Many names are in use for work knives with a replaceable blade: carpet knife, cutter knife, scalpel, Japanese knife, safety knife or utility knife. For clearer distinction, we call only knives with a trapezoid blade or hook blade carpet knives.

How do you snap off a cutter knife blade?

A cutter knife has snap-off blades with 6–13 predetermined breaking points, depending on the blade size. You can break off the blade at these points, for example with a blade snapper, pliers or against a hard object. We explain this in more detail in the cutter knife guide (in German).

Which knife suits your task? We give manufacturer-independent advice by phone, by video or on site: 0211 – 97174619.