Replaceable blade knives
The skill and time required to sharpen dulling knife blades is a trouble too much for most people nowadays. There is a wealth of very reasonably priced new and very sharp blades, most of which keep their edge well. A similar huge range of handles is available to take these blades and store a fresh supply. The increasingly popular snap-off blade can be allows up to a dozen new sharp points per strip. They are available in several sizes ~ the most popular are known as 18mm and also 9mm.
Trapezoidal sliding blade ~ plastic ~ by Stanley
Scalpel handle ~ SM No3
Pencil knife ~ plastic ~ five blades ~ coloured
Pencil knife ~ metal ~ colours
Trapezoidal sliding blade ~ metal ~ generic