Benchmade 51BK Balisong Butterfly Knife G-10 Handle (4.25" Black)

Item #BHQ-9249
MSRP: $350.00
Our Price: $297.50
Try Benchmade (Butterfly) instead


  • Overall Length: 9.25"
  • Blade Length: 4.25"
  • Cutting Edge: 3.75"
  • Blade Thickness: 0.11"
  • Blade Material: D2
  • Hardness: 60-62 RC
  • Blade Style: Spear Point
  • Blade Grind: Flat
  • Finish: Black
  • Edge Type: Plain
  • Handle Length: 5.00"
  • Handle Thickness: 0.48"
  • Handle Material: G-10
  • Color: Black
  • Frame/Liner: Titanium
  • Weight: 3.30 oz.
  • User: Right Hand, Left Hand
  • Pocket Clip: Tip-Up
  • Knife Type: Butterfly
  • Lock Type: Latch
  • Brand: Benchmade
  • Model: 51
  • Model Number: 51BK
  • Country of Origin: USA
  • Best Use: Recreation
  • Product Type: Knife

Be sure to view our other Benchmade Balisong Butterfly Knives in stock!

The Benchmade Morpho Balisong 51BK Knife is a larger version of the Benchmade Balisong 32. The 51BK Morpho Balisong Butterfly features a black finished premium D2 steel blade with black G10 handles. The hand polished hardware, jeweled blue titanium liners and Ti carry-clip provide the perfect accent to this great Butterfly Knife. BM51BK

Get a Kydex sheath for the Benchmade 51, click HERE!

Need a Benchmade Balisong Sheath to fit the 51? Pick one up HERE!

Customer Reviews

10/10 AM buying it again!
Zack D. on May 6, 2016

I own a kimura 7, a Benchmade 67, and now this beautiful black beast. This is my favorite of the 3. It flips on autopilot for me, honestly. I'm working on buying a second one for safe keeping, just because its so beautiful and amazing. The g10 is amazing, and the look of the whole knife is godly. And the way it feels in your hand..... OH YES!

Jason Y. on Jan 5, 2018

Flips great, super high quality, smooth action, comes EXTREMELY sharp, and the coating is flawless.

Minor dings and fading anodization
Zeba p. on Jul 2, 2019

Not sure why my knife came with small scratches on the g 10 and slightly faded anodizing on the upper left edge of the bite handle liner, but the flipping and sharpness of the blade makes up for most of it. 4.5/5

Light but I like that
Brett R. on Oct 31, 2019

It almost disappointed me when I picked it up, it was so light. As I used it and begin to bang it into my fingers and walls and desk, I realized it was actually very good that it did not weigh a lot even though that made me think it was cheap at first.

Alan M. on Jan 17, 2015

Nice flipper. Came literally razor sharp for me. It is also very light compared to most balisongs

Great knife
dawson r. on Dec 25, 2016

Run to it if you got the cash.

Beautiful beast
Paul z. on Jun 4, 2017

I'm not going to go off on the specs and the pro's and cons. This beauty is light as has been stated in the previous reviews. I had been looking at getting one of these for awhile. It was hard to choose between this and the Bladehq green. This was cheaper with the black blade so I went with this. It is a very beautiful knife. Comes sharp as all hell, forgot to latch it and reached in my pocket, Just little pressure and my finger is gashed up good. When I was looking for my first quality Bali this was In The top three and it definitely is worth the money. My other Bali is a tachyon 3. If your between the two then here is my two cents. If you want to learn to flip get the tachyon, if you want a great EDC that still flips we'll go with this. I prefer the weight and length of the tachyon but this knife has a certain simplicity to it's construction that makes it much better for EDC and actual knife applications.

Great Balisong!
Miles W. on Feb 26, 2020

I purchased one of these knives after buying a 51 with the satin blade. The pictures don't do the knife justice, the black coating looks even better in person. My only complaint is that there was a small burr on the blade edge, but you can't go wrong with a BM51 for this price.

Pretty D NICE
Kevin B. on Sep 12, 2015

In the past I had an original balisong from the 80's. If you find one let me know, I will grab it! This knife is very nice. Balance is quite good. You will get an awesome knife for a great price! One honest suggestion, put Scotch tape on the blade, that way you will not slash up your fingers. The blade is very fine which I greatly appreciate. Awesome knife! You will not be disappointed!

Light, Nimble, and Stylish
Greg E. on Apr 14, 2015

The best way to describe this knife is that it just makes the tricks easier. It feels very tightly under your control. It's extremely light, about half the weight of a 62, and almost flips like it doesn't even have mass. The design is incredibly cool and the latch is a good compromise between spring and free swinging. Probably the best flipper on the market for the price if you can afford it.

Beautiful flipper
Nick V. on Jun 16, 2018

Ive had this knife for almost a week it was a birthday present the blade doesn't come razor sharp but you can still sharpen and it isn't that light i mean I heard that it was too light but it came heavier than I thought it would be and it just flips beautifully it is better than my CCCS

I love this knife
Vincent D. on Feb 16, 2016

I like this knife better than my 67. It's lightweight, smooth, and is very sharp. When you flip it you can feel the difference between quality and crap and its high quality this knife. Unfortunately this knife dosent come with factory loctite so u have to do it yourself. Don't put too much bc it will get in washers little is more. . And do blade hq they let me exchange mine bc the loctite got into washers and my spring latch broke. They were nice enough to replace it for me with no problems even though it was my fault. They don't get A+++ they get E+++++ for excellence. They even send you knife packaged well and cleaned. Thanks BLADE HQ AND BLADEPLAY

Pretty Good
Scott D. on Apr 17, 2017

Bought this instead of a trainer, cut my hand 14 times in the first day and a half of having it... Pretty good Kidding aside, the 51 is a beautiful knife aesthetically and functionally, with no blade play when it isn't wanted, excellent blade coating, and an incredibly sharp D2 blade.

Benchmade 51
chris j. on Mar 25, 2015

Just received it and it I'm happy as can be with it.Another Gem BladeHQ. Thanks again boys

shane b. on Jan 15, 2016

I love it. It's not the best flipper due to its light wieght but don't let that stop you from buying one, it's still very good, and it looks great with the black blade.

Light, well made and classy
Tucker G. on Sep 27, 2015

I received this beautiful knife as a birthday present from my girlfriend, and I have to say that I'm in love with it. To start, the knife itself comes packed and shipped nicely, in the typical blue Benchmade box, with a nice draw string bag inside to house the knife itself. My first impressions (after flipping a kimura for a few weeks!) was how damn light this thing is! Doing rollovers is lightning fast, the thing feels like a feather! Now, if you dislike light knives, or if you have been flipping a heavy bali for awhile, I would definitely be wary if you plan on getting this beauty, as it clocks in at around 3.3 oz, and this can't definitely take some getting used to (I cut myself 3 times the first night getting used to it xD). Moving forward, the "spring latch" is a cool feature as well - while it isn't the traditional spring latch we saw on the 42, it is still superior to the basic t-latch you see nowadays - as it keeps the latch away from the blade nicely as well as having the satisfying spring when you unlock the bali. Also, the blade itself is made out of the usual d2 steel, which feels nice and well made - no complaints here. Screws all seem to be holding up too. To sum it up, this knife is nice if you enjoy lighter balis, or if you are looking for something different - similar to what I was hoping for. However, if you have been flipping kimuras forever, this will definitely take some getting used to. I definitely plan on eventually getting Ti handles for this (probably from flytanium when he releases the v4s), as personally I prefer a bit of a heftier feel to my balis. All in all, you can't go wrong with Benchmade, and they definitely delivered with this well made and classy looking bali. 5/5 would recommend.

Austin O. on Feb 5, 2017

This is by far the best flipper on the market right now! If you've got the money then you should turn all other flippers down and get this one! I can certainly say this is my fav flipper

Better than I expected
Cole T. on May 21, 2017

This is my first high quality balisong, and I am blown away. The fit and finish is phenomenal. I had very high hopes and expectations of this knife, which usually sets me up for disappointment, but this knife delivered. In fact, it's even better than I expected. What a work of art. Benchmade just got a new fan. EDIT: Thanks to BladeHQ as well! Shipped very fast and they responded to my shipping inquiry within a day. BladeHQ just got a new fan as well.

This things amazing!
Brayden v. on Jan 25, 2019

I got this as an Xmas present and I’ve wanted it for about 2 years so I finally got it today and it’s better than I thought! Very sharp, and bouncy flipper. I personally love lighter knives and this is my perfect weight for flipping. 10/10 would buy

Victor B. on Jul 15, 2016

This is my first butterfly knife with g-10 scales and I have to admit I'm very surprised about how great it feels in my hand. I'm having a great time flipping and I love it so much I'm getting one for my brother.

Light and Stylish
Mary A. on Dec 21, 2015

I got this knife for myself as an early Christmas gift. It's wonderful! All my friends love playing with it. It is lightning fast. Comes sharp out of the box, with a little carry pouch. However, I do have this issue where if I'm flipping it for about 30 minutes, the screws begin to loosen up. Some loctite blue will fix this issue easily. :) 10/10 would recommend to a friend.

Amazing lightweight EDC flipper
Mason O. on Dec 19, 2021

I love this knife with a passion. It's extremely lightweight, perfectly balanced, wonderfully crowned spine, sharp edge and tip, and above all else: An absolute beauty.

Dawson b. on Jul 22, 2016

This is an excellent butterfly is very fluent and smooth, as well as light. Two thumbs up.

Smooth operator
Juan M. on Aug 14, 2019

the weight and balance provide neutral handling. the G10 scales provide good, but not too much grip. the anodized and machine turned liners provide some nice contrast against the black scales. I love the shape of the blade and it came super sharp.

Great for begginers
Julio P. on Jan 19, 2018

This knife is a perfect starter knife, it’s very light weight which makes the cuts with learning not punishing. It’s a must own

Try It Atleast Once!
Connor J. on Jan 5, 2018

I got my hands on the limited run of blue G10 variants of this knife, still with the DLC blade, and I have to say it was a beauty! To start, the D2 steel is the best I've ever used. It comes razor sharp and I've never needed to sharpen it since besides a strop or two. In terms of flipping, the knife is on the lighter side but is still very good! You can do basically anything with it, and the crowned spine is very comfortable for chaplins/rollovers. I only have two complaints: 1.) The handles and blade do rub and after it a bit it does wear on the edges of the DLC 2.) The screws are a nightmare to take out sometimes and I ended up stripping one of the smaller ones while replacing the pocket clip. Highly recommend the buy if they go back on sale.

Everyone Gets a 51
Brett K. on Jan 25, 2018

It's the honest truth, a good knife from a good company. It will get you started flipping, and will cut FOREVER. you can beat on this thing forever, you can use it, forever. While this has never been my edc, or my go to flipper, it will always have its place. If you are a beginner I would definitely point you to the second hand market of reddit, on r/balisong, on instagram under #balisongsale, and even the facebook group. You will find a good deal on a used 51. But there really is nothing like a brand new knife to catch your eye and make you drool. buy it today! Its worth it!

Great EDC
Quint M. on Feb 28, 2018

I love this knife so far! I'm an intermediate flipper, it is really light so doesn't carry momentum when doing rollovers as well as other heavier balisongs. I am getting a bit of blade rub which is wearing off a bit of the black finish no matter how tight the pivots get while still keeping free movement of the handles (-1 star). It is pricey as hell but feel it's a good quality knife. I recommend this for a beginner and EDC knife but if you are a flipper already you might be a bit disappointed at the performance due to how light it is. Hope this review helps someone.

Near perfect
Michael M. on Jan 30, 2019

If you are interested in edcing a bailsong look no farther. My 2 complaints are I am not a fan of the coated blade (the non-coated one is cheeper and looks nicer), and for nearly $300 I would like a steel better than d2 for edc purposes. This is also a great first major flipper for someone getting into bailsongs.

My screws fell out
Kyle B. on Sep 7, 2019

I think the title says it all my first day after receiving the knife the screws fell out, but other than that the knife is beautifully made I still love and will do my best to try and get it replaced

Blade HQ Copyright © 2022 Blade HQ. All rights reserved
Give Feedback