Collection boxes
- for blunt blades
- special closure
- in 4 sizes
Art. no. US21
At a glance
Prices in EUR, net – for business customers only. Shipping: €14 flat rate within Europe, free of charge from €300 goods value (Shipping costs, in German) · Delivery time on request
| Quantity discount | net / pc. |
|---|---|
| from 20 pcs. (−3 %) | 8.72€ |
| from 50 pcs. (−6 %) | 8.45€ |
Cutting depth 37 mm | Plastic housing | Adjustable cutting depth
The Tortoris S21 is a safety level 1 safety knife with automatic blade retraction. The blade retracts as soon as the thumb releases the slider.
The housing is made of plastic and is particularly ergonomic shaped, with a large thumb slider that is also particularly smooth to operate. The knife is therefore designed for frequent use of up to 1,000 cuts per day.
With a simple conversion, the S21 is suitable for both right- and left-handed users. The cutting depth can be set in 8 steps from 0 (transport lock) to 37 mm. Thanks to the magnetic holder, the blade is changed without additional tools directly at the workstation. With a featherweight of under 50 g, the knife lies comfortably light in the hand even during long working periods, and the integrated Transport lock also protects the blade when stowing and carrying.
The S21 is universally applicable – from logistics and shipping to retail branches, automotive, leather and textile processing, and production. It has proven particularly effective in the film and paper industry when splicing rolls: the flexible blade can be extended and curved easily to cut cleanly through long paper or film rolls. You will find further safety knives in our Safety knives overview.
Which materials is this knife made for — and where does it reach its limits?
The S21 opens sealed cartons along the adhesive tape – the shallow cutting depth setting cuts the tape without scoring the goods underneath.
The narrow, flexible blade cleanly cuts off the lids and flaps of folding cartons and thin corrugated board without touching the contents.
The segment-free polystyrene blade cuts polystyrene and foam boards in a single pass without crumbling.
Not every safety knife is built the same – and you only notice it when it matters in everyday use. In the knife know-how section we show you at a glance how the Tortoris S21 performs in the most important respects: from the safety mechanism and grip quality to blade performance. This lets you judge whether it suits your application. If you have questions about the choice, we are happy to advise you personally.
Automatic blade retraction — the blade retracts by itself as soon as you release the handle, no need to push it back manually.
All safety levels explained →
Adjustable cutting depth: yes.
Plastic (PP/PA) — lightweight and cost-efficient, for occasional to regular use.
Everything about the Tortoris S21 in two compact PDFs: the product flyer summarises features and applications – the technical data sheet provides dimensions, blade specifications and safety information. Both are free to download.
Technical data, blade change instructions and safety notes – DIN A4
Download →The Tortoris S21 is supplied with a KB3-N9-6 (polystyrene blade, 60° tip, without snap-off segments). The knife only accepts polystyrene blades of this system – make sure they are compatible when buying. Our recommendation for everyday use: the KB3-N9-6. Overview of all cutter knife blades
Besides the Tortoris S21, we offer alternatives with a different focus: the USK023 and the USK022 use a standard 9 mm blade in a metal housing with an exposed stainless steel rail, but without adjustable cutting depth. The Martor Secunorm 380 reaches considerably further with a cutting depth of up to 8 cm for heavy cutting tasks. The US11 scores with a sturdier metal housing for more powerful cuts.
Safe 23automatic blade retractionCutting depth 60 mmBlade change possible17.40€ net
View USK023Safe 22automatic blade retractionCutting depth 40 mmBlade change possible17.40€ netView USK022
Secunorm 380automatic blade retractionCutting depth 76 mmBlade change possible14.34€ net
View UM380001
Safe 11automatic blade retractionCutting depth 36 mmBlade change possible10.23€ netView US11Complement the Tortoris S21 with matching accessories: collection boxes for dull blades, lanyards as a safety cord, cutting rulers for precise cuts and holsters for safe storage.
Frequently asked questions about the Tortoris S21 – we answer them here in detail. If you have further questions, we are happy to help you personally: To the contact form
View all Tortoris products →This knife is a sharp working tool. Use only as intended. Keep out of the reach of children. Wear suitable protective gloves if necessary. Replace blades safely in accordance with the blade change instructions – do not make any improper modifications.
