The What & Why of materials used to make them.
Is a Silvery White soft natural material which is non magnetic and isn’t very dense which means its also very light compared to steel. It is highly resistant to corrosion and when mixed with other materials it becomes an Alloy which is the form we use it in garden tools.
Its not strong or hard enough to be used for a blade but is ideal for handles and when designed well like on Bahco SL products it can produce very lightweight and stiff alternatives to other materials.
High Carbon Steel
As the name suggests it Steel with a High Carbon content, the carbon strengthens the steel and gives it the ability to be harden by heat treatment.
The best blades are made from high quality High Carbon Steel as they are super hard, can produce a super sharp fine cutting edge but one that can also be re-dressed/ sharpened as and when required. After use they do needed to be cleaned and oiled/lubricated otherwise they will begin to rust. If you think of the old ??? we use to make in this country which were very High Quality High Carbon Steel they would always rust if left outside they were often kept in a old oily rag to keep them in good condition. So Rust is actually in the case a sign of good Quality.
Most are made from a natural products like cellulose, coal, gas, salt & crude oil but then go thru a chemical process changing their structure to create various forms of plastic. It can produce items quite cheaply which are lightweight, good strength in certain directions and cant corrode, often used for cheap, lightweight handles on smaller rakes and various other parts of many tools.There are 7 different types of plastic so which can be fully recycled and some that sadly cant. 🙁
This is an alloy of Iron with Chromium in it, this produces a thin layer of oxide on the surface which prevents corrosion of the alloy below. This leaves a shiny stainless effect which is very attractive, easy to clean and reduces the amount of soil which will still to the blade in the form of spade in gardening. The process of changing Iron into Stainless Steel leaves the material slightly weaker & more brittle. This last point is important for garden tools and is why proper digging spades are made hardened Steel to deal with tough work, impacted ground etc. Stainless spades or forks are designed for well worked or soft ground just the same for trowels & hand forks.
Is of of course a naturally occurring material harvested from living trees which has then either been seasoned or kiln dried to take the excessive moisture out of the wood. Its an organic and renewable material source of many forms and has been used for a long time to help make gardening tools. Mostly used for handles from hoes to forks to shears with different wood from various trees for a huge wide variety of tools. Wood was also used before iron to make simple digging blades in draw type like hoes. It makes for a very tactile material to hold not as cold as steel or aluminium but often heavier than either with often a larger diameter required for the same strength. Boxwood was used for Trowels, Ash for Spades and even Magnolia for Shears.