Knife Review: Ontario Knife Company – Black Bird SK-4

When Paul Scheiter was asked about the name of the Ontario Knife Company Black Bird SK-5, he joked that it was in the hope OKC would consider making different versions. Well here is the second Black Bird, the SK-4, a more compact version of Paul’s original design; is it only the first of many?

 photo 05 OKC SK-4 SK-5 P1230061.jpg

The Blade and Handle Geometry:

Most knife specifications have a basic description of the blade geometry, but in this section I will be taking a more detailed look at geometry and balance.
 photo 28 OKC SK-4 grind P1250055.jpg

Using a set of gauges and precision measuring equipment including a Vernier protractor, callipers, fixed radius gauges and the unique Arc Master adjustable radius gauge (the one that looks like a crossbow).
 photo Knife measuring P1180483.jpg

These measurements have been tabulated and are presented along with a few reference blades (8″ Chef’s Knife, 5.5″ Santoku and the popular Fällkniven F1).

Key aspects such as the primary bevel angle, grind type, blade depth, blade thickness, length, weight are detailed, along with balance information.

The ‘Balance relative to the front of the handle’ tells you if the knife will feel front heavy, or if the weight is in your hand (a positive value means the weight is forward of the front of the handle). The ‘Balance relative to the centre of the handle’ indicates how close to a ‘neutral balance’ the knife has in the hand.

In the case of full convex grinds the approximate centre of the grind is used for the primary bevel angle estimate.

 photo SK-4 paramentersV2.jpg

The blade is made from 154CM steel.

Explained by the Maker:

The reasons for certain design choices may not be clear when simply looking at an object, so this section is intended to give an insight into the thinking behind a design by speaking to the designer themselves.

Unfortunately I can’t always get time with the designer so will use this section to include relevant information about the knife and its designer.

The design principles of the SK-4 are generally the same as they were for the larger SK-5, so I shall refer readers to the SK-5 review for further information:
Ontario Knife Company Black Bird SK-5 Review

A few more details:

The Black Bird SK-4 arrives in a cardboard box with lift off lid.
 photo 01 OKC SK-4 Boxed P1230041.jpg

The knife and sheath are packed separately, with the knife wrapped in a plastic bag.
 photo 02 OKC SK-4 Box open P1230046.jpg

There is a thin cardboard sheath over the blade.
 photo 03 OKC SK-4 Box contents P1230049.jpg

With all packaging removed we get to see the SK-4 and its sheath.
 photo 04 OKC SK-4 P1230053.jpg

Bare-bones simplicity, the SK-4’s blade is a shorter version of the SK-5 blade.
 photo 06 OKC SK-4 blade P1230066.jpg

While we are looking at the blade, this is a close-up of the blade tip with factory edge.
 photo 07 OKC SK-4 blade tip P1230068.jpg

Though the design is simply, I’m glad to see it does have a choil.
 photo 08 OKC SK-4 choil P1230072.jpg

The G10 handle slabs are secured with three hex bolts.
 photo 09 OKC SK-4 bolts P1230076.jpg

A nicely formed lanyard hole is included.
 photo 10 OKC SK-4 lanyard P1230080.jpg

Incorporated into the beautifully simple design is a sharp edged spine for striking sparks from ferro-rods.
 photo 11 OKC SK-4 spine P1230087.jpg

A guard stands just proud of the handle to help protect your fingers from slipping forwards.
 photo 12 OKC SK-4 standing P1230090.jpg

That sharp spark-striking edge runs the entire length of the spine.
 photo 13 OKC SK-4 spine edge P1230094.jpg

In keeping with the design principles, the handle lines are very simple, but importantly all edges are nicely rounded.
 photo 14 OKC SK-4 handle P1230095.jpg

Taking a closer look at the rounding of the G10 handles.
 photo 17 OKC SK-4 handle finish P1230102.jpg

Just like the SK-4 is a reduced version of the SK-5, so is its sheath.
 photo 18 OKC SK-4 sheath P1230106.jpg

For the retaining strap, a single-direction press-stud is used, meaning it can only be opened by pulling in one direction.
 photo 19 OKC SK-4 sheath press stud P1230103.jpg

On the back is a PALS/MOLLE mounting system which can also be used for fitting to large belts.
 photo 20 OKC SK-4 sheath PALS P1230110.jpg

Effectively you have the choice of two different belt loops as you can use the PALS/MOLLE mount strap as well.
 photo 21 OKC SK-4 sheath PALS woven P1230113.jpg

It is possible to adjust the retaining strap (this turns out to be crucial) to get the fit just right.
 photo 22 OKC SK-4 sheath retainer adjustment P1230116.jpg

Inside, the sheath has a felt lining for the blade.
 photo 23 OKC SK-4 sheath felt P1230120.jpg

The sheath also incorporates a drainage hole.
 photo 25 OKC SK-4 sheath drainage P1230130.jpg

The SK-4 in its sheath.
 photo 24 OKC SK-4 sheathed P1230127.jpg

What it is like to use?

I have been looking forward to this since I heard the SK-4 was being made. For the sharp eyed amongst you, you may have noticed the blade has no markings on it at all, as this is a pre-production sample (but is exactly as the production version will be), so I’ve had it a little while to give it plenty of use.

The SK-5 has turned out to be one of my favourite trail knives. It is my go-to when it comes to grabbing a medium fixed blade, but not any longer. Now I might equally go for the SK-4.
The 1″ shorter blade and 1″ shorter handle gives you a saving of 2″. Doesn’t sound that much, but the effect is significant.
 photo 26 OKC SK-4 SK-5 sheathed P1230132.jpg

Where I couldn’t just throw the SK-5 into a pocket, the SK-4 is small enough to fit fully inside most coat pockets, making the choice between taking a folder or a fixed blade easier. Despite the smaller dimensions the SK-4 is a very capable knife, much more so than almost any folder. (For heavier work, I’d still go with the SK-5.)
 photo 27 OKC SK-4 SK-5 unsheathed P1230135.jpg

If you are used to large knives, the SK-4 can initially seem a bit too small for anything other than light tasks.
 photo 15 OKC SK-4 in hand P1230097.jpg

Take up a power grip on the SK-4 and you realise you can apply a lot of force into the cuts. Though the handle doesn’t protrude from your fist, the rounded butt of the handle allows it to press into you hand very comfortably and not give you any hotspots while you work with it. The amount of blade available is plenty, even for pretty heavy work, so all you lose with the shorter blade is the ability to chop, and a limitation on the size of wood you can split by batoning.
 photo 16 OKC SK-4 in hand P1230099.jpg

The only issue I have identified with the SK-4 is actually with the sheath. Due to the shaping of the handle, the position of the retaining strap falls onto the wide part of the handle. It means that even when adjusted to a tight fit, the knife can easily still be pulled part-way out exposing nearly an inch of cutting edge. If the strap is not really tight, you can pull the knife out completely without opening the strap. Unfortunately the press-stud also marks the handle. As delivered from OKC, I was able to pull the knife out of the sheath without releasing the retaining strap, so please ensure you check yours and adjust it to be as tight as you can (then check you can’t pull the knife out all the way).

Factory edges – instead of opening that can of worms, let’s just say that whatever the quality of the original factory edge, you will need to re-sharpen your knife (unless you are very wealthy).
So the SK-4 was set for a Wicked Edge. Starting off with the Advanced Alignment Guide to get the blade set up for consistent future sharpening, this first time needed a reprofile to bring the edge angle back to 40 degrees inclusive angle
 photo 31 OKC SK-4 wicked edge P1250143.jpg

Freshly re-edged, the eager Wicked Edge is ready to bite!
 photo 33 OKC SK-4 wicked edge P1250548.jpg

The combination of a great edge and the SK-4’s geometry had it breezing through smaller branches leaving very clean cuts.
 photo 29 OKC SK-4 clean cut P1250161.jpg

On this particular day I found myself with a rapidly approaching sunset as I’d lost track of time while working with the SK-4. It wasn’t fatigue that stopped me, just the failing light.
 photo 30 OKC SK-4 sunset P1250167.jpg

Review Summary

The views expressed in this summary table are from the point of view of the reviewer’s personal use. I am not a member of the armed forces and cannot comment on its use beyond a cutting tool or field/hunting knife.

Something that might be a ‘pro’ for one user can be a ‘con’ for another, so the comments are categorised based on my requirements. You should consider all points and if they could be beneficial to you.

_______________________________________________ _______________________________________________
Things I like What doesn’t work so well for me
_______________________________________________ _______________________________________________
Compact and capable fixed blade. Sheath retaining strap not ideally placed, and marks the handle.
Edge geometry makes this a great slicer. Handle can feel a bit blocky.
Well rounded handle avoids hot-spots. 154CM can be hard work to sharpen.
Spine is great for striking sparks from ferro-rods.
Minimalist yet functional design.

Useful Links:

The Ontario Knife Company.
BA Blades – The UK’s official importer of OKC products.

 photo 00 OKC SK-4 feature P1230062.jpg

 

Discussing the Review:

Please feel free to add comments to the review, but the ideal place to freely discuss these reviews is on a forum. If you started reading the shorter forum version of the review, but followed the link this full exclusive review, please return to that forum to discuss the review there.
If you read the review entirely on Tactical Reviews, please consider one of the following to join in any discussion.

EdgeMatters – Sponsored Reviews (UK based Forum for Knife Makers and Collectors)

BladeForums – Knife Reviews (US based Forum for Knife Discussion)

CandlePowerForums – Knife Reviews Section (Largest and Friendliest Flashlight Community Forum)

Knife Review: Ontario Knife Company Black Bird SK-5

The Ontario Knife Company Black Bird SK-5 review is the third of a three-knife review series featuring the Black Bird SK-5, RD Tanto and RTAK II. (See – OKC Group Review.)

 photo 01 OKCtrio sheathed P1140542.jpg

The Black Bird SK-5 is a survival knife designed by Paul Scheiter and is intended to be highly functional and yet very simple.

 photo 13 Blackbird angle2 P1130908.jpg

The Blade and Handle Geometry:

Most knives specifications have a basic description of the blade geometry, but in this section I will be taking a more detailed look at geometry and balance.
 photo 30 Blackbird measuring2 P1140190.jpg

Using a set of gauges and precision measuring equipment including a Vernier protractor, callipers, fixed radius gauges and the unique Arc Master adjustable radius gauge (the one that looks like a crossbow).

These measurements have been tabulated and are presented along with a few reference blades (8″ Chef’s Knife, 5.5″ Santoku and the popular Fällkniven F1).

Key aspects such as the primary bevel angle, grind type, blade depth, blade thickness, length, weight are detailed, along with balance information.
 photo 29 Blackbird measuring P1140186.jpg

The ‘Balance relative to the front of the handle’ tells you if the knife will feel front heavy, or if the weight is in your hand (a positive value means the weight is forward of the front of the handle). The ‘Balance relative to the centre of the handle’ indicates how close to a ‘neutral balance’ the knife has in the hand.
 photo 31 Blackbird balance P1140196.jpg

In the case of full convex grinds the approximate centre of the grind is used for the primary bevel angle estimate.

 photo OKC Parameters BlackbirdRDTantoRTAKII.jpg

The blade is made from 154CM steel.

Explained by the Maker:

The reasons for certain design choices may not be clear when simply looking at an object, so this section is intended to give an insight into the thinking behind a design by speaking to the designer themselves.

Unfortunately I can’t always get time with the designer so will use this section to include relevant information about the knife and its designer. The following information was noted from an interview with Paul Scheiter by Adam from Equip2Endure

Starting with the name, why is it the SK-5? Well, the ‘SK’ of ‘SK-5’ stands for Survival Knife and the ‘5’ is for its 5 inch blade length, so SK-5 allows for a possible future series with an SK-4 and SK-3.

The concept of this knife is to have sheer simplicity and to achieve maximum function because of that. There is nothing gadgety on the knife, and it only has the bare basics. This gives a knife that has everything it needs and nothing that it doesn’t.

The result is something that is very comfortable in the hand which you can use for hours on end. There are no abrupt angle changes anywhere that your hand would come in contact with, so you are not going to get hotspots and blisters. This is really important for a survival knife where you will be doing a lot of wood processing and splitting.

A notable point is the steel choice of 154CM; in addition to there being a good compromise of edge retention and corrosion resistance, it allows for there not to be a powder-coat on the blade. Amongst other things, not having the powder-coat makes it easy to strike a ferro-rod.

The full flat grind gives the ideal cutting geometry; it stays as thin as possible for as long as possible, and reduces the calories used when cutting wood.

A spear point tip puts a little more metal behind the point, making it less prone to breaking if it gets torqued. The tip itself is placed in the dead centre line of the blade making tasks, such as the initial shaping of a bow drill pit, straightforward as this knife will drill very nicely.

The pommel of the knife is flat and perpendicular to the blade so that if you wanted to use it as a spear head (which would not be recommended, but sometimes it may be a necessity), you can carve a shelf into a piece of wood so the pommel seats perfectly onto this, giving you thrusting power, then you put the lashing around the handle to complete the spear.

Blade stock thickness at 0.13 inches was chosen as a sweet spot where you can confidently baton with it but not take away too much from wood carving which is the primary intention.

At various shows, Paul has noted that people have generally been surprised that it is a lot lighter than it looks.

On a final note about how to carry the knife, Paul Sheiter’s preferred carry option is not to wear the knife on his belt but to use a high over-the-shoulder strap/band (like a cross-body sling bag) as it allows the knife to be kept in sight to the front of the body and if wearing a winter coat you don’t have to lift the coat to access the sheath.

A few more details:

Just as with the others in this series, the Black Bird SK-5 comes in Ontario Knife Company’s standard knife box.
 photo 01 Blackbird boxed P1130826.jpg

Inside the box the knife has a cardboard protector over the blade, and the knife is not fitted into the sheath. There was also a letter explaining that this knife had upgraded G-10 handle slabs.
 photo 02 Blackbird box contents P1130833.jpg

The first proper view of the Black Bird and its sheath.
 photo 04 Blackbird with sheath2 P1130851.jpg

Before going back to the knife, a quick look at a few details of the sheath. On the back, the sheath has a PALS/MOLLE strap for mounting on a pack, vest or load carrier.
 photo 05 Blackbird sheath back P1130856.jpg

The press stud used on the retention strap is a military specification type where you can only release it from one direction.
 photo 06 Blackbird sheath popper P1130860.jpg

It is possible to change the fit of the retention strap using the Velcro adjustment.
 photo 07 Blackbird sheath detail P1130866.jpg

Inside the sheath is a felt liner.
 photo 08 Blackbird sheath liner P1130878.jpg

As well as there being PALS webbing on the front of the sheath, here you can also see the drainage hole at the bottom to allow water out.
 photo 09 Blackbird sheath drainage P1130885.jpg

Back to the knife and its details. On one side the maker and model are engraved on the blade near next to the handle.
 photo 10 Blackbird engraving P1130889.jpg

There are three details I’d like focus on in this photograph:
– The generous lanyard hole allows for easy fitting of a lanyard.
– Inside the lanyard you can see evidence of the water-jet cutting and slightly imperfect fit of the handle material, but on the outer edges of the handle and blade tang have been ground to a smooth finish.
– We are looking at the handle grip hook which gives plenty of purchase for all tasks.
 photo 11 Blackbird hook detail P1130897.jpg

Although the handle slabs are flat sided, they have been well rounded to remove sharp edges. Three bolts are used to secure the grips.
 photo 14 Blackbird grip P1130910.jpg

A close look at the blade tip showing the blade-flat surface finish as well as the factory edge and its finish.
 photo 15 Blackbird tip detail P1130917.jpg

One of my personal preferences, a sharpening choil.
 photo 16 Blackbird choil P1130919.jpg

As mentioned earlier, the handle slabs and blade tang are ground/sanded to a completely flush fit.
 photo 17 Blackbird grip detail P1130924.jpg

A sharp edge is left all along the spine meaning you can strike a ferro-rod from any part of the spine that suits you.
 photo 19 Blackbird along the blade P1130936.jpg

Though not a mirror finish, you can see the reflection of the handle on the blade flat so you could use the knife for signaling.
 photo 21-27 Blackbird along the blade flat P1140162.jpg

Unlike the other OKC knives in this series of reviews, the Black Bird’s sheath has only a single retaining strap. There is enough room for the knife to come about half an inch out of the sheath with the retaining strap closed.
 photo 22 Blackbird sheathed P1130972.jpg

For the last photo in this section, we have en extremely close view of the peely-ply G-10 handle texture.
 photo 26 Blackbird texture P1140138.jpg

What it is like to use?

As the designer Paul Scheiter noted earlier, the SK-5 does feel lighter in the hand than you would expect – immediately manoeuvrable and easy to use. This is largely thanks to the full flat grind keeping just enough steel in the blade for strength without being overly thick and heavy.

There is no ‘ideal blade length’, as everyone has their own preferences, but being the only Black Bird so far, the choice of 5 inches for a general purpose survival knife is really hitting the spot for me.

To give an idea of scale, here it is next to the Fällkniven F1 and a Spyderco UK Pen Knife.
 photo 23 Blackbird size P1130984.jpg

At 5″, the blade is half the overall length of the knife. Combining this with the full flat grind and full tang, even though the blade is 5″, the balance point is brought right back into the hand (see ‘The Blade and Handle Geometry:’ section), and this is the reason it feels light and easy to handle.

With this blade length you still have great control over the point and enough length to make batoning easy (if you need more than 5″ to baton, you should probably choose smaller wood or be making wedges for splitting instead).

Overall the package is small enough to carry easily, immediately making it more likely to be your survival knife (as a ‘survival knife’ is the knife you have with you when you need it).

The Black Bird is extremely comfortable in the hand, though the grip is a little boxy due to the flat sides.
 photo 32 Blackbird in hand P1140303.jpg

Not to get started on the subject of factory edges (which by necessity have to be created quickly, typically with belt sanders, and are usually not the best edge that knife can have), but in this case I need to mention the factory edge on the Black Bird sample I received. Check back to the measurements I took and you see it was a 58 degree inclusive angle out of the box; this is more like an angle you might choose for an axe. My initial testing was with the factory edge including comparing it to the other OKC knives. (OKC said this was an anomaly as the factory edge is not normally that steep)

Despite such a large edge angle it still cut very well just requiring a higher angle of attack for each cut. Unsurprisingly it was by far the most controlled carver of all three.
 photo 08 OKCtrio Blackbird stick P1160293.jpg

Despite not needing a sharpen at this point, I wasn’t satisfied with the factory edge angle, so decided to reprofile to around 38 degrees. Even using DMT diamond stones, the 154CM steel proved to be very hard to work and the reprofiling took me a good four hours. The edge bevel is around three times as wide as the original factory edge. Was it worth it? Well, YES, a complete transformation!

Reprofiling the edge has taken a capable cutter and made it supremely efficient and eager. On a simple paper cut test it now glides through with a push cut where previously it cut perfectly well but needed some drawing across the edge. In wood I have to be careful not to over-cut. (Remember to sharpen your knives to suit you and don’t be afraid to change the edge angle)

Another characteristic this knife has is its inoffensive look. By this I mean the fact that it has a SAK style spear point which makes it look more utilitarian than many ‘survival’ knives on the market. If other people are more comfortable when they see the knife you are more likely to carry it and have it with you when you need it (if you are bothered what others might think). Obviously when sheathed you can’t see this, but overall it is easy to carry unobtrusively. If you take it out to whittle or use it for frivolous cutting tasks it doesn’t look like a weapon. It might seem a minor point, but so far I’ve found this knife getting more positive reactions than any other I’ve carried.

Review Summary

The views expressed in this summary table are from the point of view of the reviewer’s personal use. I am not a member of the armed forces and cannot comment on its use beyond a cutting tool or field/hunting knife.

Something that might be a ‘pro’ for one user can be a ‘con’ for another, so the comments are categorised based on my requirements. You should consider all points and if they could be beneficial to you.

_______________________________________________ _______________________________________________
Things I like What doesn’t work so well for me
_______________________________________________ _______________________________________________
Excellent Handling and Balance. Grip could be more contoured.
Comfortable for extended use. Factory Edge too steep.
154CM steel with great edge retention. 154CM is harder to sharpen than other steels.
Full Flat Grind.
Showers sparks from ferro-rods.
Aftermarket sheaths available.

 photo 28 Blackbird angle4 P1140165.jpg

 

Discussing the Review:

Please feel free to add comments to the review, but the ideal place to freely discuss these reviews is on a forum. If you started reading the shorter forum version of the review, but followed the link this full exclusive review, please return to that forum to discuss the review there.
If you read the review entirely on Tactical Reviews, please consider one of the following to join in any discussion.

EdgeMatters – Sponsored Reviews (UK based Forum for Knife Makers and Collectors)

BladeForums – Knife Reviews (US based Forum for Knife Discussion)

CandlePowerForums – Knife Reviews Section (Largest and Friendliest Flashlight Community Forum)