Assisted Opening Knives

Assisted Opening Knives

shrade assisted opening knife image

An assisted-opening knife is a type of folding knife which uses an internal mechanism to finish the opening of the blade once the user has partially opened it using a flipper or thumb-stud attached to the blade. 

Assisted opening knives merge function and speed to create a mechanism that opens a blade as fast and smooth as a switchblade. 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. When the knife is in the closed position, the blade is held in place by means of torsion springs and an additional blade lock (optional). As the user applies manual pressure to the thumbstud to open the knife, a mechanism such as a torsion spring moves along a track in the liner and rapidly rotates the blade into the open and locked position.

Other trade names for assisted-opening knives are: Forward Action Spring Technology, A/O Knife, Torsion Assist Knife, Assisted Knife, Spring Assist Knife, Spring Assisted Knife, Quick Release, Quick Draw, Alternative Automatic, Outburst, SpeedSafe, Blade Launcher, S.A.T (SOG Assisted Technology), and the Semi-Auto.

Assisted Opening Knives

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Kershaw LARGE Cryo II Tanto Blackwash Speed Assisted Opening Knife 1556TBW

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End Date: Monday Oct-8-2018 13:51:35 PDT
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Kershaw Leek Black 1660CKT Flipper Speed Assisted Opening Knife Safety Lock USA

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Kershaw Al Mar AM-4 Flipper Speed Assisted Opening G10 Knife BOX 2330

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1660 Kershaw Leek Knife silver plain Blade handle *New Blem* assisted opener

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Kershaw Gray Dividend Assisted Straight Stonewash Folding Pocket Knife 1812GRY

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New FOX KARAMBIT  Straight Folding Pocket Knife! Claw Spring Assisted Opening

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Kershaw 1620C Camo Scallion Ken Onion Plain Edge Assisted opening Knife NIB

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Kershaw NATRIX Black Flipper SpeedSafe Assisted Opening Folder Knife BOX 7007BLK

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Kershaw Leek BLACKWASH 1660BLKW Speed Assisted Opening Knife NEW IN BOX USA

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10" ULTRA THICK Folding Assisted Open POCKET KNIFE Cleaver Hunting Blade Razor

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Kershaw 1600 Chive Assisted Opening Ken Onion Knives Knife New *Blem*

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Kershaw Leek Flipper Speed Assisted Opening Orange Knife CLAM Pack 1660OR USA

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Smith & Wesson M&P Spring Assisted Opening Tactical Folding Pocket Knife SWMP4LS

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10" ULTRA THICK Folding Assisted Open POCKET KNIFE Cleaver Hunting Blade Razor

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Kershaw DISCONTINUED Green & Black LEEK Spring Assist knife w Safety 1660OLBLKST

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Kershaw - SPEED BUMP Spring Assist UNIQUE LOCK knife DISCONTINUED model 1595 G10

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KERSHAW - Al Mar AM-3 G-10 Spring Assist SPEEDSAFE A/O Flipper knife KAI 2335

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Smith & Wesson M&P LARGE Design Assisted Opening Knife Glass Breaker SWMP9BTS

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10" ULTRA THICK Folding Assisted Open POCKET KNIFE Cleaver Hunting Blade Razor

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KERSHAW "USA" - Blackwash LEEK Assisted SPEEDSAFE Knife w/ SAFETY LOCK 1660BLKW

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1776 Kershaw Link pocket knife assisted opening New Blem* Made in USA

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KERSHAW "USA" - BLUR Tanto BLACKWASH PS spring assist SPEEDSAFE knife 1670TSTBW

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Kershaw Leek Speedsafe Assisted Open Tactical Pocket Knife 1660 14C28N USA New

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Discontinued KERSHAW usa - C27 LEEK Spring Assist NON-CORROSIVE knife 1660C27H3

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8.5" RAINBOW STILETTO SPRING ASSISTED FOLDING KNIFE Blade pocket open switch

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End Date: Thursday Oct-11-2018 17:54:12 PDT
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Kershaw 1812 Black Dividend Assisted Open Folding Knife Pocket Folder

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Kershaw Gray Handle Blackwash Link Assisted Straight Folding Knife 1776GRYBW

$36.09
End Date: Thursday Oct-18-2018 8:25:12 PDT
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Kershaw Leek Black Red Assisted Open Tactical Pocket Knife 1660RDBLK 14C28N USA

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Kershaw Scallion Smoke Black Red Flipper Assisted Opening Knife USA 1620BRHP

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Kershaw 1955 Black Showtime Spring Assisted Open Folding Knife Pocket Folder

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Kershaw 1660 Leek Ken Onion Assisted Opening Knife CUSTOM ENGRAVE YOUR TEXT NIB

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Gerber Outrigger Assisted Opening Knife Partially Serrated 7Cr17MoV Blade New!

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TACTICAL Assisted Open Pocket Knife TANTO RAZOR FOLDING Blade Gunmetal D2 Steel

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Kershaw Blue Link Assisted Blackwash Straight Folding Pocket Knife 1776NBBW

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New CNC Assisted Opening Conversions Wood handle Pocket Folding Knife VTF110

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Smith & Wesson M&P MAGIC Flipper Assisted Opening Knife with Safety Lock SWMP6B

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Kershaw Black Oxide Blackwash Link Assisted Serrated Folding Knife 1776GRYBWST

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Kershaw Showtime SpeedSafe Assisted Open Folding Knife 1955 1955X

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Kershaw Blur Tanto Blackwash Assisted Opening Knife NEW IN BOX USA 1670TSTBW

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Kershaw Black Oxide Blackwash Leek Assisted Composite Folding Knife 1660CBBW

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SOG pocket knife Twitch II LT Assisted opening Free Shipping USA

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12" GIANT TACTICAL Assisted Open Pocket Knife CLEAVER RAZOR FOLDING Blade NEW

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KERSHAW-GRID-2200-Flipper-Knife-Drop-Point-Blade-SpeedSafe® assisted-opening

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Kershaw Al Mar AM-3 Flipper Speed Assisted Opening Knife BOX 2335GRN AM3 OLIVE

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Kershaw Blur Camo Handle Sandvik SpeedSafe Assisted Opening Knife USA 1670CAMO

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1776TGRYBW Kershaw Link Tanto Point pocket knife assisted opening New Blem USA

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Kershaw Blur Stonewashed Navy Blue SpeedSafe Assisted Opening Knife USA 1670NBSW

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Kershaw Black Oxide Blackwash Link Assisted Plain Folding Tanto Knife 1776TGRYBW

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Assisted Opening Knife Reviews

More About Assisted Opening Knives

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.

Although commonly confused with switchblade knives, a switchblade can be opened automatically simply with the push of a button, but the user of an assisted-opening knife must open it about one-quarter of the way (45°) before the mechanism opens the knife the rest of the way. The difference is important legally; because the blade does not open simply "by the push of a button or by force of gravity" the assisted-opening knife is typically not considered a switchblade, and may escape the restrictions applying to those in many places.

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.

The first assisted opening knife was designed by Blackie Collins in 1995 and was named the "Strut-and-Cut"; it was based on the strut of his Ducati motorcycle. A similar concept was developed three years later by knifemaker Ken Onion with Onion's idea based on a similar mechanism in his Harley Davidson motorcycle. Onion applied for a patent on his design in 1998.