Kitchen Knife Edge Retention

↑ Back/Next ↑

A Rockwell rating is an indicator of how hard the knife is. In general, the lower the Rockwell, the less the edge retention (less sharp and lose sharpness faster). However, lower Rockwell knives are more durable (when it comes to bone cleavers, they tend to use lower Rockwell knives to compensate for the impact and have a steeper sharpened angle of around 45 degrees per side). Higher Rockwell knives have longer edge retention (can hold the sharpness for a longer period) but lose durability.

If you have to give the Rockwell an edge retention timeline for home use, you get something in these timeframes:

  • HRC 51 – 5 min *
  • HRC 52 – 1/2 days *
  • HRC 53 – 3 days *
  • HRC 54 – 1 week *
  • HRC 54 – 1/2 weeks *
  • HRC 55 – 1/2 weeks *
  • HRC 56 – 1/2 months *
  • HRC 57 – 2/3 months *
  • HRC 58 – 3/4 months *
  • HRC 59 – 4/5 months *
  • HRC 60 – 5/6 months *
  • HRC 61 – 6/7 months *
  • HRC 62 – 7/8 months *
  • HRC 63 – 8/9 months *

+ Regular honing with a honing rod before needing whetstone maintenance if used at home for double ground knives (sharpened on both sides). **

*The above indicator is based on my personal experience in a restaurant setting and based on all-purpose knives and not specialized knives.

**Warning: You should never use a honing rod on a single bevel knife. (Yanagiba’s, Sakimaru, Deba, Unagisaki etc.)

How did I come up with the above indicator?

It is tested in a restaurant setting where we prepare a standard menu with the same ingredients (we do hours of prep work within a team setting. Which means one person does 30+ min of cucumbers only, and the other does the salad in 30+ min, etc.).

We need to portion size the Tuna to slice for sashimi

Of course, other factors play a role in what you use it on, how much force you use, how you cut, how heavy the knife is, at what angle the knife is sharpened at, and what blade steel is used. I have added the indication since many of the viewers wanted a rough estimate. I converted it for home use of approximately 5/10 min a day.

Professional kitchen:

Rockwell 56: Knife died after approx. 30/45min. (Victorinox manages to reach 45min. Some other cheaper brands manage to survive 30 min despite the claim of a Rockwell of 56)
Rockwell 57/58, They manage to get the job done longer, but a hone is needed after the prep was done (approx. 1.5/2 hours).
Rockwell 60/61, It managed to survive 4 hours, but a hone is needed.
Rockwell 63+, it survived for 2.5 days (10 hours before a hone).

For home use, this all depends on how many knives they have, how often they cook, and how well they take care of them. (see chart above)

This is based on my experience with knife Rockwell and how I got my estimates while testing the knives in a restaurant setting.

Regular restaurant prep work

Prep work on a Friday, 60 avocados (we use paring/petty knife, and for dragon sushi rolls, we use a thinner knife like a petty/utility knife), 60 cucumbers, 8 mangoes, 12 lettuce, 3 red leaf lettuce, 20 whole salmon, Tuna, 25 kilo’s (Approx. 55 pounds), 2 whole beef tenderloin (probably 3kg each 6.5 ish pounds) and more fish like sea bass, etc.
These are only the Sushi prep, excluding Teppanyaki and warm dishes, we have a sushi team of 5 to cover these, and it needs to be done before 4 PM since we need to eat staff meal at 3 PM before the rush hour/when guest arrive.

Tuna, portion-sized sinew, and bloodline removed, ready for storage or to be sliced into sashimi or nigiri slices.

If we split the team of 5, we have approx. have 4 hours to prep everything. 5 times a day, 4 hours prep every day, and depending on which station you cover, you may use the knife for 7/8 hours.

Rockwell 56: Knife died after 30 ish cucumbers a hone is needed (approx. 30/45min).
Rockwell 57/58, They manage to get the job done longer, but a hone is needed after the prep was done (approx. 1.5/2 hours).
Rockwell 60/61, It managed to survive 4 hours, but a hone is needed.
Rockwell 63+, it survived for 2.5 days (10 hours before a hone).

The above timeframe is for veggies prep only.

If we take the above time and translate it to home cooks 5 min (5 minutes of actually cutting) prep a day (they are slower in prep and prep less per day):

Rockwell 56: 9 days
Rockwell 57: 18 days
Rockwell 58: 24 days
Rockwell 60+: 48 days
Rockwell 63+: 120 days

And that is without honing and only veggies prep.

Above with honing, you can get longer edge retention and most likely even double the days, and you can even hone more often after one honing session.

Rockwell 56: 18 days
Rockwell 57: 36 days
Rockwell 58: 48 days
Rockwell 60+: 144 days
Rockwell 63+: 240 days

This is a rough estimate since I was asked to add an edge retention timeframe in the videos. I just had fun with some rough calculations, but this pretty much says that you don’t need a stone for a long period of time if honed correctly with high Rockwell knives. And above is assuming you cook no cheat meal/ visiting restaurants (so some will experience longer edge retention than others etc.). In the end, I came up with the first chart to give everyone a rough estimate.

You can leave your questions in the comment section below.

▶ If you want to know what knife you should buy you can read 
the following article ''Choosing your knife''. 
▶ On my youtube channel, I have reviewed a lot of different knives.
You can watch the playlist by clicking here.  
▶ Click here, if you want to search for other
kitchen knives on:  Amazon.
▶ Click here, if you want to search for other 
Chinese knives on AliExpress.
▶ Check out my gear on Kit: 
▶ Check out my recommendation on Amazon:
Full Disclosure: 
If you purchase from these links I get a small commission 
that goes towards supporting the channel and website.
As an Amazon Associate, I earn from qualifying purchases
▶ If you have any questions about Japanese knives made in China 
or about some of the brands feel free to ask it in the comment section below.   
Thank you for your support and feedback.  
▶ Want to work with me? Please use the contact form by clicking here.

Leave a Reply

Your email address will not be published.

Back to top button