KERF Case For iPhone 5/5s Review – 100% Natural Wood Case

  • Editor Rating
  • Rated 3 stars
  • 60%

  • KERF Case For iPhone 5/5s
  • Reviewed by:
  • Published on:
  • Last modified: December 19, 2018
  • Cosmetic Appeal
    Editor: 70%
  • Design & Build Quality
    Editor: 90%
  • Features
    Editor: 30%
  • Function
    Editor: 70%
  • Value For The Price
    Editor: 50%

The KERF Case is an iPhone 5/5s case made entirely of 100% natural wood.


Recent studies show the iPhone is one of the top contenders in the mobile market and the data seems to show the device's consumer-base is continually growing each year. Due to this immense popularity, there is an influx of manufacturers producing cases for the device with many of them taking unique approaches to the design and build materials used within their products.


KERF is an excellent example of this, manufacturing protective cases for the iPhone 4, 4s, 5, and 5s that are made of 100% natural wood. Now you might be think they are just copying a company like Carved whom also utilizes real wood in their cases however KERF has a drastically different approach due to one large reason. Unlike Carved, KERF cases are made ENTIRELY of 100% natural Wood materials and do not harness any plastic or synthetic components. I will get more into detail about how they accomplish at a later portion in this review.

Design & Build Quality

The KERF cases use strictly natural materials and stray away from the cheap plastic that many of their competitors harness in their products. Each case is made from a single piece of wood and lined with natural cork to offer a secure fit while staying environmentally friendly. There are multiple wood finishes offered with each variant ranging in price as some types of wood are more expensive than others.


The materials are of an exceptionally high quality and unlike the wood used within the Carved cases, it feels and smells just like real wood and does not feature the shiny gloss coating that makes it resemble plastic. The natural cork material is lined meticulously within the inside edges of the case in a clean manner which doesn't take away from the unique look of the case.

IMG_8986The KERF case has cutouts to allow access to all the necessary iPhone buttons, cameras, and ports. The rear cameras cutout's large appearance is unappealing, but I soon realized this cutout is oversized to help remove the iPhone from the case with your thumb. This is necessary since the natural cork holds such a tight “Friction Fit” that it can be difficult to remove without resorting to this method.

KERF supplied us with a sample that was in a Sycamore finish. It which wouldn't have been my first choice as the look seems a bit more feminine, but that is just personal preference. Had I been given the choice, I would likely have settled with Oak, Mahogany, or Walnut as I think those are the most pleasing to the eye.


As you can likely tell from the photos, the case does not offer 360-degree protection and chances are you'll want invest in a quality adhesive screen protector to aid the KERF's protection capabilities. However, the wood is thick enough to protect against accidental drops, dings, or scratches yet slim enough to fit in your comfortably in your pocket without taking up too much space.

With the cases starting at $59, there isn't any real concrete features that can justify such a high price-tag. However, these cases are artisan made, crafted out of a single piece of natural wood and hand-sanded to 600 grit. This means you are essentially paying a premium price due to the high cost of materials as well as the manual labor put into producing these one of a kind cases.


I put the KERF case to the test equipping it to my iPhone 5 on a daily basis for about a week and a half. After my time using the case, I have come up with a few observations concerning case's performance in a real-life situation.

To my surprise, the wood material did not show any noticeable wear after my period of use and the case looked just like it did the day I received it. This may differ for some of you as I generally take good care of my devices and don't put them in harms way. Many competing cases that I have reviewed in the past such as the OtterBox Preserver Series were not able to carry out this feat and showed noticeable wear spots after the same period of daily use.  It is true that you won't get the full protection you would with an OtterBox case however the protection offered is likely adequate for most consumer needs especially when coupled with an affordable screen protector.


Another thing that was noticeable was how lightweight the case is and how it did not result in much of a bulk or weight increase to my iPhone 5, something that many competitors products suffer from. I had initially anticipated the opposite as wood is heavier than plastic or rubber in most cases, but KERF managed to calculate the precise dimensions which allow a slim and light fit without sacrificing durability.

Lastly, I was impressed at how well the case held my iPhone 5 using the cork lining. KERF boasts that it is the only case on the market that uses a “Friction Fit” design. Here is what the KERF website had to say about this unique technology:

What do we mean by Friction Fit?

In simple terms, every wood iPhone case made has a mechanical connection to the phone. It snaps in, wraps around, or slips on in more than one piece. Have you ever struggled to remove a case from your iPhone? Nearly dropped it or flung it across the room?  We asked the question why. There must be a better way.

Machined from a single piece of wood, the case is precise to 1/1000 of an inch. In developing a case that would hold your iPhone safely, yet still was easy to slip on and off, we came up with a simple, yet effective patent-pending solution.


Lining the inside edges with thin cork solved several problems:

1) Grip – The cork grips the iPhone with its high coefficient of friction. The cork compresses slightly when your iPhone is inserted

2) Thermal Expansion – Wood moves, the cork absorbs this movement by compressing

3) Padding – The cork adds an extra level of protection to your phone


We not only chose cork because it is a natural material, produced sustainably from trees, but also for its science.

Simply put, because of a complex materials science equation involving Poisson's Ratio, cork is amazing.

When compressed, it rebounds, for a long time. Rubber and other squishy materials eventually loose their ability to rebound. Think about why corks have been holding back wine for hundreds of years…

Cork has been used in fine musical instruments, as flooring, padding, gaskets, and many other uses. It is durable and perfect for its application in Kerf Cases.


Looking at the concept on paper it seems genius and utilizing it on a 100% natural wood case is a no-brainer, however I wasn't sure how practical it would be in a real-life situation. After experiencing it first-hand, I must say the Friction Fit design worked flawlessly and far exceeded my expectations.


In the end, KERF's line of natural wood cases are some of the best wooden cases on the market and part of a select few that are considered 100% environmentally friendly. However, with the expensive materials and artisan craftsmanship comes a premium price tag and for that this case is more of a work of art than a fully function iPhone case. Personally, I'm more interested in the protection and feature benefits when buying a case priced over $50+. However, I could see this type of case fitting in with the artsy and “green” community as you're truly getting a one of a kind product that is made from natural materials and hand crafted to perfection in the USA. If this sounds like the type of product you're looking for then I think the KERF case is a solid buy, however if you're on a budget and are willing to sacrifice the build quality and materials used then you'll likely want to go with the more affordable Carved Case instead.

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