How is a knife made?
Kitchen knives can vary in price from a few pounds to hundreds, so just what do you get when you pay more for a knife? And how do they come into being? Here's a quick overview to help you out...
In a nutshell, your money gets you:
- Better Materials and Workmanship
An expensive kitchen knife is made from better quality materials throughout. The blade will be made from higher quality steel that will have undergone various processes to make it perform better as a cutting tool. Equally the handles will be made from materials which are more durable and more comfortable to hold as the price increases.
- Better Handling
Just like a car, a more expensive knife is easier to handle and more comfortable to use for long periods than a cheap one.
- Better Cutting Performance
All knives are sharp when they are new, but the more you spend on your knife the longer the sharpness will last. There is no such thing as a knife that stays sharp forever, but you will find that better quality chef’s knives are much easier and less hassle to sharpen than cheaper ones.
How a knife is made
Traditional kitchen knives are ‘fully forged’, meaning that they have been struck into shape from a piece of red-hot steel. A fully forged knife is strong because all of the metal parts have been formed at the same time from a single piece of steel. Traditional knife foundries used 120 ton drop hammers to forge knives from bars of red-hot steel.
Modern foundries are far quieter, more efficient and environmentally friendly than their forerunners. The drop hammers have gone, replaced by more efficient hydraulic presses and precise use of induction heating technology means that no energy is wasted heating up excess material.
1 - Flat pieces of steel are cut to length and inserted into a hydraulic forging machine.
2 - Small induction heaters heat a portion of the piece of steel to red heat.
3 - Hydraulic presses push the ends of the piece of metal to make the red-hot part bulge.
4 - A second set of hydraulic presses forces a mould into the red-hot steel bulge to form the shape of the knife bolster.
5 - A third hydraulic press pushes out the shape of the knife blank from the original piece of steel.
6 - The knife blanks are heat treated. They go into a giant computer-controlled oven and are repeatedly heated and cooled to change the crystalline structure of the steel making it harder, stronger, and suitable for years of fine cutting.
7 - Shaping – the knife blade is ground into its basic shape.
8 - The handle is attached by a series of robots that each perform a single stage of the process. The result is a permanently fixed handle that is neatly finished and polished. In some factories old craftsmen who used to do this job by hand now supervise columns of robots, using their skill and experience to adjust the machines where necessary.
9 - Final sharpening – the cutting edge is applied to the knife. The angles at the edge are measured by laser to ensure perfectly even cutting performance.