What is HAP40 steel

What is HAP40 Steel? HAP-40 Steel Review For Beginners

HAP40 is Japanese steel usually found in high-end Japanese chef knives. However, Spyderco also started using this new steel to make some of their high-end pocket knives. If you’re eyeing a hap40 steel, you’re probably wondering what type of steel it is and what its pros and cons are.

Before you buy that hap40 steel knife, read this hap40 steel review to get more information about it. We’ll look into the performance of hap40 high-speed steel by discussing its chemical composition, hardness, edge retention, corrosion resistance, ease of sharpening, resistance to chipping, and other helpful info you need to understand HAP40 steel.

What is HAP40 steel?

HAP40 is high-speed tool steel manufactured by the Japanese Hitachi Metals Ltd using the PM (Powdered Metallurgy) process. It’s made of a rich mix of elements which gives it a perfect balance of hardness, edge retention, and toughness. It also features a fine microstructure which makes it reliantly easy to sharpen compared to other steels with the same level of hardness.

What is HAP40 steel

Is HAP40 stainless? HAP-40 is not stainless steel. This contains only 3.70-4.70% Chromium content. This is less than the 12% chromium needed for a stainless, meaning it doesn’t meet the requirements for stainless steel. But that doesn’t mean hap40 steel will rust easily. The small amount of chromium will still deliver some considerable resistance against rusting and corrosion.

HAP40 steel composition

The HAP40 steel composition is a mixture of elements—namely carbon, chromium, molybdenum, tungsten, vanadium, and cobalt—that promote high hardness and great toughness.

The full HAP40 steel chemical composition is as follows:


Percentage composition (%)

Carbon (C)


Chromium (Cr)


Molybdenum (Mo)


Tungsten (W)


Vanadium (V)


Cobalt (Co)


1.27-1.37 % Carbon raises the steel strength and increases its hardness and wear resistance.

3.70-4.70% Chromium increases the steel tensile strength, hardness, and toughness. It also increases corrosion resistance.

4.60-5.40% Molybdenum increases strength, hardness, and toughness.

5.60-6.40% Tungsten adds to the steel hardenability, strength, and toughness.

2.80-3.30% Vanadium increases the steel strength, toughness, and wear resistance.

7.50-8.50% Cobalt is used to intensify the individual effects of all the above elements.

What is HAP40 steel hardness?

The hap40 steel HRC can range from 64 to 68 HRC, depending on the heat treatment used. This is extremely high hardness and makes this steel deliver long-term edge retention while increasing its wear resistance.

HAP40 steel properties

Having looked at the chemistry of HAP40, we can now easily understand what key benefits you’ll get from a knife made using this steel. Let’s see how the steel fairs in the key properties usually considered for any knife steel.

HAP40 steel properties

HAP40 steel Edge retention

The Japanese steel offered you extremely long-lasting edge retention, all thanks to its extremely high hardness (with 68HRC maximum). You can use your hap40 steel knife to do a lot of cutting for days without stropping it and it will still keep its edge sharp and highly functional.

HAP40 steel corrosion resistance

HAP40 contains little chromium content and doesn’t offer the same level of corrosion resistance as what you get with stainless steels and other steels with higher chromium volumes. Nevertheless, the little chromium it carries still does a good job at stopping corrosion in its tracks.

Manufacturers are now laminating their hap40 steel knives with stainless and anti-corrosion finishes to shield the steel from rusting and corrosion. Giving your knife a simple cleaning, wiping it dry, and oiling it can also help stop rust from attacking it.

HAP40 steel toughness

This steel offers great toughness, as Hitachi intended it by perfectly mixing its elements. This is a rare case of high hardness steel offering great toughness. The generous amounts of Molybdenum, Vanadium, Tungsten, and Cobalt are the secret behind its high toughness.

HAP40 steel knives aren’t chippy and won’t crack or break easily when put under hard use. You’ll even be surprised that this steel beats high carbon steels like ZDP-189 steel in toughness.

HAP40 steel ease of sharpening

HAP40 is a real headache to sharpen…but that’s not surprising for steel this extremely hard and wear-resistant. But if you use proper sharpening stones, you’ll be able to easily give your hap40 a hair-splitting edge. And this edge will hang around for quite long, saving you from having to sharpen your steel more often.

HAP40 steel ease of sharpening

hap40 steel equivalent

HAP40 has a pretty close chemical composition to Bohler Vandais 30, making them equivalent steel grades. The Bohler features alloying elements Carbon (1.27%), Chromium (4.20%), Molybdenum (5.00%), Vanadium (3.10%), Tungsten (6.40), and Cobalt (8.50%). These are pretty similar values to what you get with the HAP40.

And just like Hap40, the Vandais 30 is also a high-speed PM tool steel and has a high hardness of 67HRC. The two steel deliver a perfect combination of edge retention, corrosion resistance, and toughness.

hap40 steel comparison

Comparing Hap40 with other steels further helps you understand more about this steel. In this part, we’ll compare our steel with other top steels like ZDP-189 high carbon steel, VG10 stainless steel, and S30V stainless steel.

hap40 steel comparison

hap40 steel vs zdp-189

HAP40 is easier to sharpen and easily attains hair-splitting edge than zdp-189. Hap40 is also tougher and is less likely to chip, crack, or break when put to abuse and tough tasks.

Though we have seen that hap40 has excellent edge retention, ZDP-189 will hold an edge for even longer compared to this steel. Zdp-189 contains 20% chromium and will offer you excellent corrosion resistance, unlike hap40.

Overall, if you want a super-steel that gives you superior performance, go with zdp 189 steel. but if you want premium performance steel, get a hap40 knife.

hap40 vs vg10

HAP40 is quicker to sharpen, takes a nice edge, and holds it for relatively long. VG10, on the other hand, is a bit harder to sharpen but also takes a nice, long-term edge. Though HAP40 ranks higher than Vg10 in terms of toughness, the VG10 still has good toughness to it and won't chip easily under normal use. However, VG10 is stainless steel and will offer better corrosion resistance than HAP40.

hap40 steel vs s30v

Sharpening hap40 is harder compared to s30v, but the trade is that it will take a wicked sharp edge easily. Both steels offer excellent edge retention, but s30v holds its edge better than hap40. CPM S30V is stainless, so it beats hap40 in resisting rust and corrosion.

hap40 steel vs s30v

Another benefit s30v has over hap40 is that the formers knives are redly available, while the former steel will take a heck of time before you can get one.

Is HAP40 a good knife steel?

With its great hardness, excellent edge retention, and great toughness, HAP40 will make good steel for knives. The steel also sharpens quite easily, with the right sharpening system, and attains a hair-splitting edge.

This steel might not be stainless but still offers decent corrosion resistance, and it’s one of the main reasons the steel is quite popular with high-end Japanese chef knives.

Is HAP40 a good knife steel

Spyderco uses this steel to make high-end HAP40 pocket Knives which perform really well for day to day cutting tasks. They hold an edge for exceptionally long and are tough enough to handle nearly all day-to-day cutting tasks without getting chippy or cracking/breaking.

Final Verdict

HAP40 is Japan-made, high-speed tool steel. The steel offers a great combination of high hardness, edge retention, and toughness and is a great choice for making high-quality knives. it’s not the hardest steel to sharpen, and when sharpened correctly, it takes a crazy sharp edge. The corrosion resistance is decent for this steel. We hope that you have gained more insights about hap40 from this hap40 steel review to help you understand what kind of steel it is and how good it is for making knives.

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