How Does A Blacksmith Sharpen Iron?

Blacksmiths commonly forge tools such as knives and axes during their work. An essential aspect of creating a high-quality blade is the sharpening process.

When sharpening iron during forging, blacksmiths use sharpening stones such as waterstones, oilstones, and diamond sharpening stones. To rejuvenate and re-sharpen iron blades, blacksmiths may either use these stones or tools called honing rods.

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When Does Iron Need to Be Sharpened?

Iron may need to be sharpened at many points. Especially when making knives, it is important that your blades are sharp, as dull blades can be dangerous.

This added danger occurs because dull blades require more pressure to cut than sharp ones, so if your hand slips and causes you to cut yourself, the cut will likely be much deeper.

You will need to sharpen a blade after forging it, but you also may need to sharpen it throughout its lifespan. Blades become dull as they are run over surfaces such as cutting boards, and the blade’s edge bends slightly away from the board over time.

To keep your blade sharp and prevent the need for frequent sharpening, do not bang it on materials that are harder than your metal. For example, if you are a hunter, you should avoid using iron knives to cut bone, as this will deaden the knife’s edge more quickly.

However, no matter how cautious you are, you will eventually need to sharpen your iron blades. This can be done using a sharpening stone or honing rod.

Honing Rods

A honing rod is a rod made of steel, diamond, or ceramic, that is used to realign a blade’s edge. This rod works by straightening or uncurling metal that has become blunted by folding it over itself back down into a sharp edge.

To use a honing rod, blacksmiths (or anyone using a knife) will hold the blade on the honing rod’s base and slide the blade across the rod down and away from themself.

Generally, honing rods are quick fixes for dull blades and can be useful for realigning damaged blades.

However, they are not as effective at sharpening as whetstones because, over time, the edge of the blade will become so rounded it cannot be rejuvenated.

In this case, you will need to use a sharpening stone to sharpen your blade and create a new edge for the piece.

Sharpening Stones

Whetstones, also known as sharpening stones, are stones used to sharpen blacksmith’s blades. Like honing rods, these tools can be used to sharpen a blade that has gone dull, but they can also be used to sharpen a newly created blade before use.

These stones have been used for hundreds of years and are reliable and effective sharpening methods that have stood the test of time.

Unlike honing rods, whetstones do not bend and realign dull edges – they create new ones. When the blade is ground against the stone’s surface, small, dull portions of the blade are removed, making the surface sharper and clearing the dull section. By removing the dull metal on the blade’s edge, a new edge is formed.

Furthermore, sharpening stones are versatile and can be used for virtually any blade, such as knives, axes, or chisels. One major aspect of their versatility is their grit number, which is an indicator of how harsh a stone’s surface is.

Stones with a grit number of about 400 are coarse and ideal for initial work sharpening a dull, newly forged blade. When the grit number is about 1,000, it will create an edge sharp enough for a kitchen or pocket knife, and a grit number of 2,000 will be razor-sharp.

Fortunately, many sharpening stones have different grit levels on each side to expand its versatility. After forging a blade, blacksmiths can begin by sharpening it on the 400 side and finish it on the 1,000 side.

The main types of sharpening stones are Waterstones, oilstones, and diamond sharpening stones.


Many high-quality sharpening stones are made in Japan. Most Japanese sharpening stones must be wet before they are used, therefore earning the name “Waterstones.” Now, Waterstones are made all over the world and are a great option for those looking for a sharpening stone that will rapidly sharpen your blade without requiring you to buy expensive oil.

Waterstones may need to be completely submerged in water and allowed to “fill up” before use, or they may simply require their surface to be wet and remain wet for the duration of the sharpening process.

The wet surface creates a slurry of water and sharpened particles, allowing the blade to be sharpened easier and faster than on other types of stones.

This Whetstone Cutlery with 400/1000 Grit (Amazon affiliate link) is an example of a water stone that is meant to be soaked for 5-10 minutes before use. Each side has a different grit level, so you can use it for any blade, from knives to axes. Like most water stones, this will help you smooth and recondition your tools.

Water stones are often recommended for maximizing sharpness and polishing your blades, offering some advantages over diamonds and oilstones.

However, while water stones are less messy than oilstones and do not require oil purchase, they tend to be softer and wear down more quickly than oilstones.


Oilstones are similar to water stones, but they are lubricated with oil rather than water. Buying honing oils can make them more expensive to use long-term, but you can use common oils such as olive oil effectively for a cheaper option.

Generally, oilstones are the cheapest type of sharpening stone. They are accessible and easy to use but can be messy due to the excessive oil they use, leaving oil around your workspace and on your tools.

Moreover, they wear down unevenly over time, creating a slanted surface that is difficult to flatten and may necessitate the purchase of a new stone.

Diamond Sharpening Stones

Diamond sharpening stones are made of synthetic diamonds attached to metal plates.

These stones are fast, effective, and more durable than other types of sharpening stones because they retain their shape for longer periods of time without becoming slanted or curved.

Moreover, they are the neatest option if you are working in a home workspace because they do not require water or oil.

For example, this 8-Inch DuoSharpplus Bench Stone (Amazon affiliate link) can sharpen very quickly without oil or water, allowing you to sharpen your blades with less mess and more convenience.

Diamond stones are also very versatile, as they can be made in “quad-stones,” where each of its four sides has a different grit number. In addition, they can be used with water or dry, creating flexibility when you decide which sharpening stone to use.


After forging an iron blade, blacksmiths usually sharpen it using a sharpening stone.

Water stones are the most high-quality, but many blacksmiths have turned to diamond sharpening stones for their flexibility and versatility in grit, which is vital during the early stages of sharpening.

When blades begin to wear down, blacksmiths may use honing rods to sharpen their blades quickly.

However, if the blade is very worn, they will use the sharpening stone to form a new sharp edge for maximum efficiency.

Hi there! My name is Jack and I write for ToolsOwner. I have a passion for everything related to tools and DIY projects around the house. You often find me in my workshop working on new projects.