Bear OPS Bear Song IV Butterfly Knife Aluminum w/Trainer (4.38" Black) B-400B+TR

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MSRP: $199.99
Our Price: $89.95
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Item #BHQ-74868


  • Overall Length:9.75"
  • Blade Length:4.375"
  • Blade Material:1095
  • Hardness:58-60 RC
  • Blade Style:Spear Point, Trainer
  • Blade Grind:Hollow
  • Finish:Black
  • Edge Type:Plain
  • Handle Length:5.375"
  • Handle Material:Aluminum
  • Color:Gray
  • Weight:4.48 oz.
  • Knife Type:Butterfly
  • Brand:Bear Ops
  • Model:Bear Song IV
  • Model Number:B-400-B+TR
  • Country of Origin:USA
  • Best Use:Recreation
  • Product Type:Knife


This Bear Song IV model has aluminum handles and a black finished blade with an optional trainer blade.

The Bear Song IV butterfly knife is a collaboration between BladeRunnerS (BRS) and Bear OPS. It 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 ti black finished 1095 high carbon steel clip point blade has a double tang pin design for great performance. This version of the B-400 includes an alternate dull training blade for flipping practice.


Customer Reviews

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Not worth the money
jake a.
Bought this for my son to use. Out of the box it felt cheap, the weight is not good for flipping, the handles are too blocky, and the handle slop was the worst I have seen in a long while.

I put in the training blade on and changed out all the hardware which helped, but I would not recommend this knife at all.
Cheap in every way
Andrew F.
Blade HQ took it back and fully refunded me, so good on them.
I'll just post my return request:

Just don't like it.
This is by far the worst quality blade I have ever seen. I own 10$ trainers that are better quality than this. The blade rubs the handles on both sides which is wearing off the blades finish. The back of the blade's tip makes actual contact with the handle, which is eventually going to snap the it off from flipping. The cheap tang pins are different sizes on each side of the blade, causing the handles to create a pinch effect on one side. The tang pins ARE going to break because of this. The latch does not actually function, and is actually denting the aluminum handle to the point that it can barely squeeze into its notch already. It is already rusting in the tiny screw holes at the bottom of the handles, which are very offset and abrasive to the skin. Handle play is completely sloppy.

And to top it off, the screws are soo loose you cant flip it safely without constant maintenance or applying loctite, which would void my warranty. So I definitely want to return this blade.