As a blacksmith, you probably know that purchasing a proper steel hammer for forging is quite expensive. If you need a new hammer or are interested in expanding your supply, you may consider forging your own hammer out of steel.
Hammers are made out of a multitude of steel types, but the most common include 4340, 4140, and 1045-1060 steels. These kinds of steel have better toughness, weldability, and general suitability for hammers than their counterparts.
To learn more about the steels you can use to make your hammer and the conditions they require for proper welding, keep reading.
Types of Steel For Forging Hammers
1. 4340 Steel
4340 is a tough alloy of steel well-known for its stability. When it is heat-treated and forged, it can become very strong while retaining toughness.
Heat treatment also gives it water and atmospheric corrosion resistance, making it good for working in adverse conditions.
Before heat treatment, forging 4340 must be completed at high temperatures between 2250 and 1800ºF (1230 and 980ºC). Cooling 4340 should occur using ashes or sand, not air, making it slightly messier than some steels.
If you are making any type of steel hammer in your forge, you should heat treat it to ensure it has maximum hardness and strength to endure blows against the metal you’re working on and the anvil you are using.
This heat treatment includes annealing, which is a common treatment that reduces hardness and internal stresses in the metal.
To anneal 4340 steel, you should start at a temperature of 1525ºF (830ºC) and cool it to 1350ºF (730ºC). Then, you should furnace cool it to a temperature of 1130ºF (610ºC) at 20º per hour, which will help you complete the full annealing process.
While this process is time-consuming, it will increase the hammer’s wear resistance. 4340 and 4140 steels are great for hammers due to their extreme strength.
During heat treatment, 4340 steel should also be normalized. Normalization helps create uniformity in your hammer by heating the metal to very high heat, allowing the hardness to be “normalized,” then cooling it back down. 4340 should be normalized at a temperature of about 1500ºF (815ºC).
After normalization, the steel should be hardened between 1500 – 1550ºF (815 – 845ºC) and oil quenched. It can also be hardened using a flame or induction hardening.
If welding occurs during the normalizing or hardening process, this metal’s mechanical properties can be drastically altered, so it is best to ensure welding is completed during the annealing state.
While 4340’s toughness makes it a good candidate for hammers, it can be quite difficult to cut. For easier welding and forging, you may want to try a 1045-1060 steel.
2. 1045-1060 Steel
Carbon Steels 1045-1060 are medium steels with moderate strength and toughness. It has reasonable tensile strength, meaning it withstands medium stress while being stretched before breaking. These qualities make it relatively easy to weld, and it can be through hardened to 2.5 inches (63mm), or it can be flame or induction hardened.
The moderate qualities of carbon steel 1045-1060 make it a great choice for hammers, especially if you are welding for home.
Ensuring your hammer is not as tough or strong as your anvil is important to prevent damage to the anvil, so if your anvil’s steel is lower-quality, 1045 can be a good choice.
While it is not as tough as 4340, it is easier to weld and is viable even for new blacksmiths.
To forge 1045 steel, you should start at a temperature of about 2200ºF (1205ºC) and work down to a temperature between about 1650-1700ºF (900-925ºC).
Then, your steel should be air-cooled and heat treated. The heat treatment will usually involve normalizing, hardening, and annealing.
Annealing of 1045 steel is also much faster than annealing of 4340 steel. It is annealed at 1450ºF (790-870ºC), then furnace cooled by cooling 50ºF (28ºC) per hour until the metal reaches 1200ºF (650ºC).
Normalizing 1045 steel should take place at about 1700ºF (925ºC), and the normalized steel should be cooled in still air. You can harden this steel at about 1550ºF (845ºC) to make it suitable for hammering, and perform oil or water quenching to solidify its hardness.
Finally, tempering treatment can occur between 300-400ºF (150-200ºC) and will reduce the stress on the steel, so your hammer stays intact for longer.
1045 grade steel is widely considered one of the easiest steels for tool-making due to its quick forging and relatively easy heat-treating.
It cuts well and should be simple to make into a hammer. However, it is less tough and strong than 4140 steel, so it may not last as long.
3. 4140 Steel
Like 1045 steel, 4140 is a favorite for hammers and other tools due to its enforceability and easy maintenance. While these two types of steel are very comparable, they have a few key differences- while 1045 is very easy to weld, 4140 provides a bit more of a challenge.
Furthermore, compared to the medium toughness and strength of 1045, 4140’s strength and durability give it an advantage in hammer making. Therefore, it is important to consider what you’ll be using your hammer for before you choose steel, because you may need 4140 for bigger projects.
4140 is an alloy of steel that shares many qualities, such as its toughness and general forging temperatures, with 4340 steel.
Its chromium content makes it very hard, and it maintains uniform hardness and strength throughout. This uniform hardness is important for hammers because it prevents weak spots in the metal that could cause it to break.
4140 steel has a wide range of uses and is especially common in industrial applications, such as rods and gears.
It is also widely used in tools such as nuts and bolts. This makes it a good option when making a hammer because if you keep 4140 steel to make hammers, you can use it for other purposes as well. In fact, 4140 works well for other blacksmithing tools, such as tongs.
Additionally, 4140 is less difficult to cut than 4340, so it’s perfect if you want your hammer to have the tough qualities of 4340 steel but be a bit easier to weld.
It can tolerate water quench, which will help you save money and keep tidy because you will not have to quench with oil.
Finally, 4140 is one of the cheapest known steels you can use for forging.
Now that you know which steels are best for hammers and the proper temperatures and methods to use each one, you’re ready to make a hammer!
The main steels used to make hammers are 4140, 4340, and 1045 steel. If you are making a hammer in your forge, you may want to use 1045 steel due to its simplicity and convenience.
However, if you are looking for a steel that will create a sturdy and long-lasting hammer, you may opt to use 4340 or 4140.
Generally, 4140 steel and 4340 steel are very tough and firm, making them ideal for use during forging and against your anvil.
To create the highest-quality hammer at the best price, you should make your hammer using 4140 steel.
Overall, any of these steels produce quality hammers, and you can use whatever you have on hand before purchasing new steel.
I hope this article was useful to you. Thanks for reading and good luck with your future projects!
Cheers, tools owners!