In everyday working life, cutting cardboard, foil, plastic strapping band, adhesive tape, textiles or foam is part of the daily routine – whether in goods receipt, production, warehousing or on the construction site. However, opinions differ when it comes to safety and efficiency in the workplace: "Sharp blades must be more dangerous... or are they?" The answer surprises many: studies, practical tests and ergonomic findings prove that a sharp blade is not only the more efficient choice, but also the safer one.
Sharp blades cut through the material more cleanly and precisely with a cutting edge.
Firstly, efficiency: a sharp blade cuts through the material evenly and in a controlled manner. Films and tapes do not fray, packaging does not tear, and insulation materials or textiles remain dimensionally stable. The result: clean cut edges, less waste and faster throughput times. This is a measurable productivity advantage, especially in industries with high cutting frequencies – e.g. goods receipt, order picking or disposal. Because you can work better and more efficiently. Frequent re-cutting is no longer necessary.
A blunt blade, on the other hand, 'scratches' and squeezes its way through the material, if it can get through at all.
Studies in materials engineering show that blunt cutting edges damage the fibre structure of materials such as cardboard, films and textiles. Research conducted by the Technical University of Denmark (DTU) has demonstrated that the cutting force increases exponentially with increasing bluntness – and that the edge quality decreases measurably.
In the packaging industry, it has been observed that blunt knives result in up to 40% more errors (e.g. tearing instead of cutting edge) (source: Packaging Technology and Science Journal, 2020).
Sharp blades require less force
The sharper the blade, the less force is required. This not only increases precision, but also reduces physical strain.
An ergonomic study by Marsot et al. (Applied Ergonomics, 2014) showed that sharp knives require approximately 60% less cutting force overall. This means less muscle strain, less fatigue, especially at higher cutting frequencies, and a lower error rate when using the cutting edge.
Specifically, studies are based on these differences:
(Sharp blade vs. blunt blade or blade that was blunt when it left the factory; other influencing factors such as cutting angle, etc. have been factored out).
- 1- to 2-ply cardboard: approx. 30–60% less effort required with a sharp blade
- Foil: approx. 50–80% less effort required with a sharp blade, as the foil deforms particularly strongly
- Plastic strapping band: approx. 40–70% less effort required with a sharp blade, as strapping is particularly resistant
- Foam/polystyrene: approx. 20–50% less effort required with a sharp blade
Sharp blades do not slip off so easily
A common misconception is that sharp knives are more dangerous because they are easier to cut yourself with. In fact, the opposite is true.
A sharp blade cuts through the material without jerking or jamming. This keeps the movement smooth, steady and predictable – a crucial safety advantage.
A blunt blade, on the other hand, often gets stuck and then suddenly comes loose again. The pent-up energy causes the knife to shoot forward uncontrollably – often towards the hand or body. This significantly increases the risk of the blade slipping and hitting the user.
According to a US study by the National Safety Council, blunt knives cause around 40% more workplace accidents than sharp blades. Occupational safety organisations such as the DGUV and HSE UK point out that blunt cutting tools are one of the most common causes of hand injuries. The recommendation is clear: use sharp blades from the outset and replace them regularly to prevent slipping.
Sharp blades cause fewer serious cuts.
Every cut is painful and one too many – there's no sugar-coating it. But, as paradoxical as it may sound, doctors and safety officers confirm that an accidental cut with a blunt blade often leads to irregular, crushed wounds that heal less well and carry a higher risk of infection. Smooth cuts close faster and cause less permanent damage than lacerations caused by blunt tools.
The best combination: sharp blades in high-quality safety knives
Conclusion: Sharp is safe – especially when you use the right tool.
Sharp blades
- cut precisely and gently on materials,
- require less force,
- reduce the risk of slipping and injuring yourself,
- usually result in less serious injuries in the event of accidents.
The ideal combination therefore consists of a sharp, high-quality blade and a GS-certified safety knives that incorporates highly effective safety technology. This technology safely shields the sharp blade or retracts it into the handle in good time.
That's why we at MARTOR say: for efficient cutting, the blade MUST be as sharp as possible. It CAN also be as sharp as possible because the user can rely on the safety of the MARTOR handle. We have also made blade changing as easy and safe as possible so that you always have a fresh cutting edge at your disposal.
