Bear OPS Bear-Song IV Butterfly Knife Aluminum (4.38" Satin Plain) B-400-S

For Reference: Not Actual Blade Color For Reference: Not Actual Blade Color
MSRP: $135.00
Our Price: $83.95
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Item #BHQ-13029


  • Overall Length:9.75"
  • Blade Length:4.375"
  • Blade Material:Sandvik 14C28N
  • Hardness:58-60 RC
  • Blade Style:Clip Point
  • Blade Grind:Hollow
  • Finish:Satin
  • Edge Type:Plain
  • Handle Length:5.375"
  • Handle Material:Aluminum
  • Color:Gray
  • Weight:4.40 oz.
  • Knife Type:Butterfly
  • Brand:Bear Ops
  • Model:Bear Song IV
  • Model Number:B-400-S-35009
  • Country of Origin:USA
  • Best Use:Recreation
  • Product Type:Knife


The Bear Song IV butterfly knife is a lightweight flipper that is designed to be your go-to everyday carry knife. The B-400 model features natural finished aluminum handles with stainless steel spacers and a swappable latch. The pivots have 304 bearing surfaces and phosphorus bronze washers. The satin finished 14C28N stainless steel clip point blade has a double tang pin design for great performance.


Customer Reviews

Write a review for this item
Completely satisfied
William S.
Good quality knife that balances materials and features against the price point it was built to.

I particularly like the way the two tang pins firm up both the open and closed positions. Staying locked when closed is not an issue with this Bear Ops due to the second blade pin, and the lock bar will (usually) swing open when the handles are squeezed firmly with the knife in the vertical position.

While I've only had this Bear Ops for a week, I'm impressed with the assembly. It has a great balance of close fit and easy flip. It stays locked when you lock it the closed position, but it flips smoothly and easily and has zero lateral blade play when held or locked open. 4.45 oz (measured) is a good weight for me as a novice flipper.

The only real ding I see is that the blade is not in perfect alignment with the handles when locked open. The clip point is also a little abrupt for a blade this long. That's just personal taste, but I would like to see more taper on the false edge.

As others have said, a great knife for the price. Now to see how the fit holds up over time.
Could be better
Aaron W.
Initial impressions were really good. The knife came out of the box with a great feel and everything. But,the parts break down really easily.

Pros: Good flipper
Good balance
Handles have a comfortable grip

Cons: Latch is useless
tang pins dig into the handles quickly
Loctite doesn't help with handle play
Construction flaws (uneven spacers, uneven tang pins, pivot holes on the handles don't line up with the pivot screws)
Overall a good knife, but probably not worth the $90.
Blade HQ response:
Sorry to hear about the trouble you're having. Have you tried to contact our customer service department yet ( We'd like to help you get this resolved in a timely manner. Thanks -BHQ
Under $100 cannot go wrong.
Ryan L.
I picked this up after a LOT of research... And I have to say it was definitely worth it.
It came in perfect flipping condition, just needed to be opened and closed a few times to loosen a bit, after that it flips amazingly.

I will point out that there are some minor scuffs on the handles, they're small enough that you don't notice them unless looking closely, and for the price I did not expect the bali to be perfect so I won't remove a star for it.
Really Good.
Vince W.
I've never really been a big balisong guy, but I wanted one for my collection. I bought one before at a knife show for 10 bucks, and it broke the day I got it. This is obviously 100% better. Good weight, balance, and it just feels really beefy. Definitely worth the money.
Great bali
Andrew S.
This is a great bali for beginners, it compares to my BRS replicant, good weight, everything is nice for the price.