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 black BLUR ASSISTED opening Knife 1670TBLKST tactical tanto tip. Blem

$42.95
End Date: Wednesday Mar-21-2018 21:47:24 PDT
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KERSHAW Gray DIVIDEND Assisted Stonewash Straight Folding POCKET Knife! 1812GRY

$35.83
End Date: Sunday Mar-18-2018 15:10:49 PDT
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Kershaw Leek Stainless Assisted Opening Knife 1660 Ken Onion Design Plain Edge

$35.99
End Date: Saturday Feb-24-2018 9:14:05 PST
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1660 Kershaw Leek Knife silver plain Blade handle *New Blem* assisted opener

$32.95
End Date: Monday Feb-26-2018 18:22:15 PST
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Kershaw LOT OF 3 Neck Knife & 2 Assisted Open Pocket Knives 3PC Speedsafe

$34.95
End Date: Friday Mar-16-2018 22:08:25 PDT
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KERSHAW Blue LINK Assisted Blackwash Straight Folding POCKET Knife New! 1776NBBW

$38.75
End Date: Wednesday Mar-21-2018 15:04:39 PDT
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Kershaw 2335 Al Mar AM-3 8Cr13MoV Plain Edge Assisted Open Framelock Knife

$27.95
End Date: Thursday Mar-8-2018 1:06:36 PST
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utility knife auto spring assisted tactical military

$55.00
End Date: Wednesday Mar-21-2018 16:54:20 PDT
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12" GIANT TACTICAL Assisted Open Pocket Knife CLEAVER RAZOR FOLDING Blade NEW

$29.95
End Date: Sunday Feb-25-2018 10:29:56 PST
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Kershaw Al Mar AM-3 G10 Handle Pocket Knife Assisted Opening Plain Edge 2335

$25.99
End Date: Thursday Mar-22-2018 10:14:37 PDT
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KERSHAW Black DIVIDEND Assisted Stonewash Straight Folding POCKET Knife! 1812

$31.31
End Date: Sunday Mar-4-2018 10:41:34 PST
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Kershaw Blur Assisted Opening Folding Knife 1670TBLKST Black Tanto Combo Blade

$30.00
End Date: Saturday Mar-3-2018 18:45:29 PST
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KERSHAW Scallion ASSISTED SERRATED Folding Pocket Knife 1620ST New!

$35.83
End Date: Monday Mar-12-2018 14:43:05 PDT
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KERSHAW "USA" - Blackwash LEEK Assisted SPEEDSAFE Knife w/ SAFETY LOCK 1660BLKW

$38.95
End Date: Sunday Feb-25-2018 7:32:28 PST
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1670BLK KERSHAW BLUR ASSISTED opening Pocket Knife plain edge USA NEW *Blem*

$44.95
End Date: Sunday Mar-11-2018 23:02:35 PDT
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KERSHAW Black Oxide BLACKWASH LINK Assisted Plain Folding TANTO Knife 1776TGRYBW

$36.12
End Date: Monday Mar-19-2018 18:08:35 PDT
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Ontario RAT-1 Assisted Opening Knife Black G10 Handle AUS8 Black Plain Edge 8871

$49.99
End Date: Saturday Mar-24-2018 14:21:40 PDT
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Kershaw 1955 Showtime Assisted Opening Folding Knife

$27.99
End Date: Saturday Mar-3-2018 5:42:28 PST
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Smith & Wesson M&P Spring Assisted Opening Tactical Folding Pocket Knife SWMP4LS

$43.73
End Date: Wednesday Feb-28-2018 9:41:03 PST
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KERSHAW Titanium Carbo-Nitride ASSISTED FERRITE Straight Folding Knife! 1557TI

$31.60
End Date: Saturday Mar-24-2018 12:48:51 PDT
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1660ST Kershaw Leek Knife silver combo Blade New *Blem* assisted opener

$32.95
End Date: Monday Feb-26-2018 18:22:16 PST
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TACTICAL Assisted Open Pocket Knife TANTO RAZOR FOLDING Blade Gunmetal D2 Steel

$29.95
End Date: Sunday Mar-11-2018 10:20:37 PDT
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SOG Flare Assisted Opening Pocket Knife Black Handle Satin Plain Edge FLA1001

$30.95
End Date: Saturday Mar-17-2018 9:20:47 PDT
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1776 Kershaw Link pocket knife assisted opening New Blem* Made in USA

$29.95
End Date: Monday Mar-19-2018 21:53:35 PDT
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Stainless Steel Assisted Knife

$37.16
End Date: Monday Feb-26-2018 10:14:14 PST
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Kershaw - SPEED BUMP Spring Assist UNIQUE LOCK knife DISCONTINUED model 1595 G10

$26.50
End Date: Tuesday Mar-6-2018 16:13:11 PST
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Kershaw 1660CAMO Leek Ken Onion Camo SpeedSafe Assisted Opening Knife

$38.00
End Date: Friday Mar-23-2018 20:29:12 PDT
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KERSHAW - Blackwash CRYO Hinderer G-10 Assist SPEEDSAFE FLIPPER Knife 1555G10BW

$28.95
End Date: Friday Mar-9-2018 16:08:28 PST
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1776TGRYBW Kershaw Link Tanto Point pocket knife assisted opening New Blem USA

$33.95
End Date: Tuesday Feb-27-2018 20:30:41 PST
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1600 Kershaw Chive Knife plain Blade 3" frame lock New *Blem* assisted opener

$27.95
End Date: Monday Feb-26-2018 18:22:16 PST
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KERSHAW - Al Mar AM-3 G-10 Spring Assist SPEEDSAFE A/O Flipper knife KAI 2335

$26.75
End Date: Monday Mar-19-2018 7:38:21 PDT
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KERSHAW "USA" - Black LEEK Assisted SPEEDSAFE Knife w/ SAFETY LOCK KS 1660SWBLK

$39.50
End Date: Monday Feb-26-2018 20:12:26 PST
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Kershaw Grid 8Cr13MoV Plain Edge Assisted Opening Tactical Folding Knife 2200

$29.99
End Date: Thursday Mar-8-2018 3:09:33 PST
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Harley Davidson motorcycle spring assisted knife

$37.95
End Date: Tuesday Feb-27-2018 7:47:26 PST
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Kershaw "usa" - M390 Dividend Spring Assist Speedsafe FLIPPER knife KAI 1812BLK

$120.00
End Date: Friday Mar-9-2018 12:51:05 PST
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# 3871WM Kershaw Amplitude 3.25 pocket knife Assisted Opener knives Rexford 3871

$25.95
End Date: Saturday Mar-3-2018 10:57:13 PST
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Kershaw Link 420HC Assisted Opening Blue Handle Tactical Knife 1776NBBW New!

$40.95
End Date: Sunday Mar-11-2018 3:18:22 PDT
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KERSHAW Titanium VEDDER Straight Black ASSISTED Folding Pocket Knife New! 2460

$34.35
End Date: Sunday Mar-18-2018 15:11:02 PDT
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KERSHAW - Large CRYO II BLACKWASH Hinderer 2 Spring Assist A/O Knife kai 1556BW

$28.50
End Date: Thursday Mar-15-2018 20:36:36 PDT
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12" GIANT TACTICAL Assisted Open Pocket Knife CLEAVER RAZOR FOLDING Blade NEW

$29.95
End Date: Thursday Feb-22-2018 19:40:54 PST
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KERSHAW Black Handle LINK Assisted Folder Straight Folding Pocket Knife! 1776

$31.60
End Date: Sunday Mar-4-2018 10:39:08 PST
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Kershaw Clash Assisted Open Plain Edge Black Finish Linerlock Knife 1605CKT

$27.89
End Date: Tuesday Feb-27-2018 1:50:18 PST
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KERSHAW "USA" - LEEK Assisted SPEEDSAFE Knife w/ SAFETY LOCK Ken Onion k ks 1660

$36.95
End Date: Wednesday Mar-7-2018 5:18:44 PST
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ONTARIO OD Green RAT-II 2 Black AUS-8 Plain FOLDER Folding Pocket Knife! 8861OD

$30.95
End Date: Saturday Mar-10-2018 5:58:00 PST
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KERSHAW - Large black CRYO II Hinderer 2 Spring Assist SPEEDSAFE Knife 1556BLK

$28.75
End Date: Tuesday Mar-13-2018 23:52:34 PDT
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SALE PRICE - Kershaw "usa" - BLUR Black PS Spring Assist EDC Knife KAI 1670BLKST

$43.50
End Date: Sunday Mar-18-2018 5:28:36 PDT
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Spring Assisted Open Stiletto Knife Pocket Serrated Switch Assist Blade Black 4"

$54.64
End Date: Tuesday Mar-13-2018 12:35:28 PDT
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KERSHAW "USA" - Carbon Fiber LEEK CPM-154 Spring Assisted SPEEDSAFE Knife 1660CF

$75.95
End Date: Saturday Mar-17-2018 22:45:36 PDT
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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.