Spring Assisted Vs. Automatic


A common source of confusion for new knife enthusiasts is the difference between a spring assisted knife and a switchblade knife. Even those who are familiar with pocket knives or fixed blade knives often don’t know the difference between a switchblade and an assisted knife. The confusion is easy to understand as in both cases the knife may seem to release from the handle on its own. But when you look more closely at the mechanisms which open each blade, you can quickly see the difference.

The switchblade, or automatic knife, has a button or a lever which releases the blade. The button or lever releases the tension held by a spring inside the knife handle. When the lever or button is pushed, the tension from the spring releases and launches the blade from the handle and into a locked position. Some switchblades release the blade from the side of the handle like a spring assisted or a folding knife, while others release out the front of handle (Out-the-Front or OTF).  There are very strict laws concerning the ownership and carry of automatic knives, and you should always check local regulations before purchasing to avoid problems.

The spring assisted knife, or assisted opening knife, doesn’t rely on a button or lever for opening. Instead, it uses a spring or torsion bar which doesn’t engage until the knife blade has opening momentum from another source. The best source is obviously human power engaging a thumb stud, thumb hole, thumb disc, or flipper, moving the blade forward until the spring or torsion bar engages and moves the blade open the rest of the way.

The simplest way to tell the difference is whether or not there is a button or lever. An assisted opening knife does not have a button or lever. It has some form of initializing action that requires human effort. Your thumb has to push on a flipper, a thumb stud, a thumb disc, or a thumb hole to start moving the blade. If there is a push button or a slide that releases the blade, that makes it an automatic.

Always remember to check your local laws before purchasing or carrying a knife. If you have questions, consult your local law enforcement for clarification.

Anatomy of a Manual / Spring Assisted Folding Knife

Anatomy of a Manual / Assisted knife

Anatomy of a Manual / Spring Assisted Folding Knife Manual knives are legal in most areas, which means they are extremely common. Often, this type of knife is also recognized as a “pocket knife.” Spring assisted knives are roughly the same as manual knives, but they have a spring inside the handle that helps deploy the blade much faster. Spring assisted knives typically have a … Continue reading

How does a Spring Assisted knife work?

The difference between automatic knives and spring assisted knives is how the blade is deployed. An automatic knife deploys the blade on its own (no exterior finger force) with a trigger/button. A spring assisted knife needs an external force to engage the spring. The spring mechanism in a spring assist knife is quite simple. There may different variations of the mechanism but in essence they’re all the … Continue reading

How to Care for your Spring Assist Knife

My blade sticks; it doesn’t open as smoothly or as quick as it use to.

My knife is starting to rust; I thought my knife was made out of stainless steel…what a piece of [fill in blank]!

My blade can’t slice through anything anymore; is it time for a new knife?

I just spent $$$ on my knife and I want to keep it nice: what do i do?

Above are possible scenarios on why you are reading this post: You need to know how to take care of knife and to take care of it well. Proper maintenance and care of your knife will lead to many years of good reliable cutting and slicing. Your [enter amount] investment should last you for as long as you take care of your knife. Keep in mind a cheaply made knife will eventually (whether immediately or soon) fall apart if put under rigorous use.

There are five easy steps for proper care and maintenance. How frequently you need to maintain your knife depends on how often and how hard you use your knife. Follow these steps regularly  and you will enjoy using your knife for a long time.

1. Keep your knife dry.

  • The blade (especially the edge) and metal parts of the knife can rust if exposed to .

2. Keep the pivot lubricated with a dry lubricant. Tuff Glide is a common dry lubricant used by knife manufacturers, retailers and consumers.

    • With the knife closed put a drop of dry lubricant on either sides of the pivot.
    • Open the blade, place a thin bead of dry lubricant on both sides of the knife along the pivot.

Work the lubricant into the pivot by opening and closing the knife.

3. Keep your handle lint and dirt free. Use canned air or Remmington’s Rem Oil to blow out the trapped dirt/lint.

4. Keep your blade sharp. A dull knife is a useless knife. A dull knife is also a dangerous knife.  There are many different types of blade sharpeners. I recommend the Spyderco Sharpmaker. It’s easy to use; it can accommodate most knife lengths; and it’s a great value. Below are other knife sharpener options:

5. Tighten the screws on your knife regularly. There are toolkits that specifically for knife screws: The Benchmade Folding Torx & Screwdriver Tool Kit with Knife Sharpener and the Harley Davidson Black Box Knife Service Kit offer the  widest range of tool bits for your knives.

  • Try Vibra-Tite VC-3 to minimize adjustments to your knife.
  • If you don’t want to adjust your knife, you can buy Vibra-Tite Permanent Strength Threadlocker Gel or use a bit of nail polish to permenantly secure the screws in place. (Unscrew the screw, dab some nail polish on the threads near the tip of the screw, screw it back in and let dry.)



The Thumb Stud Versus The Flipper

There are many different styles of knives in the world. Major or subtle differences can range from size of knife to type of blade to difference in the blade release to color and weight. Today we will be focusing on the blade release aspect of a knife; and more specifically the difference between the thumb stud and flipper. Keep in mind there are many variations of blade releases: The thumb hole, thumb tab/lug, nail nick, push button and dual action (which have a hidden scale/bolster release) to name a few.

The Thumb Stud

The thumb stud makes for an easy and quite common operation used to open up a folding or spring assisted knife. The thumb stud sits on the side of the blade near were the blade pivots on the handle. It makes for a comfortable way to use one hand to open the knife. One thing to consider is how close this puts your hand to the blade itself. A cautionary warning: There are many accounts of people actually cutting themselves while opening blade. Your thumb might slip and get sliced.

Benchmade Mini Barrage Knife 585S Spring Assist Axis Lock (2.91" Satin Serr)

Benchmade Mini Barrage Knife 585S

If you would like see how to open a knife with a thumb stud, watch below.

Courtesy of BladeHQ.com

The Flipper

Flipper knives offer another way to smoothly open both spring assisted and manual folding knives. The flipper is normally located on the spine of the knife as part of the blade. The blade is deployed by using the index finger to pull back on it. This not only keeps your hands at a safe distance from the blade but gives you an added finger guard once opened. The flipper in most cases will actually swing around and end up underneath the knife continuing to offer protection from accidental knife injuries. If you are concerned the safety of your thumb, a flipper knife will be more to your liking.

Smith & Wesson Black Ops SWBLOP4BS Spring Assisted Knife (3.35" Black Serr)

Smith & Wesson Black Ops SWBLOP4BS

If you would like see how to open a knife with a flipper, watch below.

Courtesy of BladeHQ.com

Both types deploy the blade with relative ease. When it comes down to getting a knife with a thumb stud or a flipper, it is all about preference and intended use.