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 USA Tactical Blur Black Tanto Sandvik Assisted Opening Knife 1670TBLKST

$44.95
End Date: Thursday Nov-9-2017 15:24:44 PST
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Kershaw USA Tactical Blur Black Sandvik Blade Assisted Opening Knife 1670BLK

$44.95
End Date: Friday Nov-10-2017 14:10:12 PST
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Kershaw USA Blur Tiger Stripe OLIVE Hdl Sandvik Assisted Opening Knife 1670OLTS

$49.95
End Date: Thursday Nov-9-2017 15:43:30 PST
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KERSHAW Black Oxide BLACKWASH LINK Assisted Plain Folding TANTO Knife 1776TGRYBW

$35.79
End Date: Thursday Oct-26-2017 13:26:43 PDT
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Kershaw LARGE Cryo II Hinderer BLACK Blade Folder Assisted Opening Knife 1556BLK

$29.95
End Date: Monday Oct-30-2017 14:35:41 PDT
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Smith & Wesson S&W Knives Large M&P Assisted Open Folding Knife SWMP4LS

$34.94
End Date: Saturday Oct-28-2017 12:26:30 PDT
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Kershaw Cryo Hinderer BLACKWASHED G10 Handle Assisted Opening Knife 1555G10BW

$28.95
End Date: Tuesday Nov-7-2017 14:59:17 PST
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Kershaw Cryo Hinderer BLACKWASHED G10 Handle Assisted Opening Knife 1555G10BW

$25.00
End Date: Tuesday Nov-14-2017 18:47:29 PST
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Kershaw 1660 Leek Ken Onion Plain Edge SpeedSafe Assisted Opening Knife NIB

$36.95
End Date: Friday Oct-20-2017 14:06:17 PDT
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Kershaw 2335 Al Mar AM-3 8Cr13MoV Plain Edge Assisted Open Framelock Knife

$27.95
End Date: Saturday Nov-11-2017 0:36:27 PST
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Kershaw 1660 Leek CUSTOM ENGRAVED SpeedSafe Assisted Opening Knife NIB

$36.95
End Date: Wednesday Nov-1-2017 12:30:58 PDT
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1660 Kershaw Leek Knife silver plain Blade handle *New Blem* assisted opener

$30.95
End Date: Sunday Oct-29-2017 19:22:15 PDT
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KERSHAW Blue LINK Assisted Blackwash Straight Folding POCKET Knife New! 1776NBBW

$37.47
End Date: Saturday Oct-28-2017 9:19:43 PDT
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Kershaw Showtime SpeedSafe Assisted Open Folding Knife 1955 1955X

$25.94
End Date: Sunday Nov-12-2017 8:10:52 PST
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Kershaw "usa" - M390 Dividend Spring Assist Speedsafe FLIPPER knife KAI 1812BLK

$71.95
End Date: Thursday Nov-9-2017 12:51:05 PST
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Kershaw "usa" - M390 Link Spring Assist SPEEDSAFE "Flipper" knife KAI 1776BLK

$76.95
End Date: Thursday Nov-9-2017 13:18:46 PST
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Kershaw Al Mar AM-3 Flipper Speed Assisted Opening G10 Handle Knife 2335 AM3

$26.95
End Date: Saturday Nov-4-2017 14:22:41 PDT
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SOG Flash I Assisted Opening Pocket Knife FSA-7 Plain Edge Light, AUS 8

$29.99
End Date: Sunday Nov-12-2017 10:21:52 PST
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Kershaw Al Mar AM-4 Flipper Speed Assisted Opening G10 Handle Knife 2330

$28.95
End Date: Thursday Nov-2-2017 15:59:02 PDT
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Kershaw USA Tactical Blur Black Sandvik Blade Assisted Opening Knife 1670BLKST

$45.95
End Date: Friday Nov-10-2017 14:10:15 PST
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KERSHAW Tan Assisted LEEK Straight Black FOLDING Pocket Knife New! 1660DSBLK

$45.91
End Date: Friday Oct-27-2017 12:13:57 PDT
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Kershaw Al Mar AM-4 Flipper Speed Assisted Opening G10 Green Olive Knife 2330GRN

$29.95
End Date: Saturday Nov-4-2017 14:21:42 PDT
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Kershaw Barstow Assisted Opening Black 3" BlackWash Folding Blade Knife 3960

$25.49
End Date: Tuesday Oct-17-2017 14:19:24 PDT
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Kershaw USA Tactical Blur Stonewashed Navy Blue Assisted Opening Knife 1670NBSW

$47.95
End Date: Sunday Oct-29-2017 11:21:54 PDT
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KERSHAW Black AM-4 Straight ASSISTED 8Cr13MoV Folding Pocket Knife New! 2330

$28.92
End Date: Wednesday Nov-8-2017 6:15:18 PST
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Smith & Wesson M&P Spring Assisted Opening Tactical Folding Pocket Knife SWMP4LS

$39.73
End Date: Tuesday Oct-31-2017 10:41:03 PDT
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KERSHAW Black AM-3 Straight 8Cr13MoV ASSISTED Folding Pocket Knife New! 2335

$26.72
End Date: Thursday Oct-26-2017 13:31:44 PDT
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Gerber Paraframe AO Assisted Open Pocket Knife Plunge Lock New Read Description

$25.99
End Date: Monday Nov-6-2017 13:55:31 PST
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Kershaw USA Tactical Blur Camo Handle Sandvik Assisted Opening Knife 1670CAMO

$45.95
End Date: Thursday Nov-9-2017 15:36:02 PST
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Reduced! Kershaw Cryo II Kershaw Hinderer Design Assisted Opening

$25.99
End Date: Thursday Nov-9-2017 14:21:01 PST
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1660CKT Kershaw Leek Knife black plain Blade New*Blem* USA assisted opener

$38.95
End Date: Monday Nov-13-2017 11:53:40 PST
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KERSHAW Black FLOURISH Straight Black ASSISTED Folding Pocket Knife New! 3935

$30.47
End Date: Wednesday Nov-15-2017 13:48:12 PST
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Kershaw Cryo II 1556BLK Assisted Plain Edge Knife

$27.50
End Date: Tuesday Nov-14-2017 12:38:46 PST
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Kershaw USA Leek Speed Spring Assisted Opening Sandvik Blade Pocket Knife 1660

$38.95
End Date: Saturday Nov-4-2017 14:08:27 PDT
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Kershaw - SPEED BUMP Spring Assist UNIQUE LOCK knife DISCONTINUED model 1595 G10

$26.50
End Date: Monday Nov-6-2017 16:13:11 PST
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SOG Tactical Black FLASH II 2 ASSISTED Plain TANTO Folding Pocket Knife! TFSAT-8

$47.42
End Date: Sunday Oct-29-2017 13:16:08 PDT
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New Kershaw Flourish 3935 CARBON FIBER & G-10 SpeedSafe Assisted Opening Knife

$31.65
End Date: Thursday Oct-26-2017 22:58:59 PDT
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1600 Kershaw Chive Knife plain Blade 3" frame lock New *Blem* assisted opener

$27.95
End Date: Sunday Oct-29-2017 19:22:16 PDT
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Kershaw USA Blur Tanto Blackwash Assisted Opening Folder Knife BOX 1670TSTBW

$41.95
End Date: Friday Nov-3-2017 16:30:37 PDT
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KERSHAW "USA" - Carbon Fiber LEEK CPM-154 Spring Assisted SPEEDSAFE Knife 1660CF

$75.95
End Date: Wednesday Oct-18-2017 22:45:36 PDT
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KERSHAW Black Handle LINK Assisted Folder Straight Folding Pocket Knife! 1776

$31.29
End Date: Wednesday Oct-18-2017 13:02:45 PDT
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5 PC RED Lot Assorted Spring Assisted Open TACTICAL Pocket Knife Combat

$25.94
End Date: Wednesday Oct-25-2017 9:01:19 PDT
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KERSHAW - Large black CRYO II Hinderer 2 Spring Assist SPEEDSAFE Knife 1556BLK

$28.95
End Date: Monday Nov-13-2017 22:52:34 PST
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Kershaw LARGE Cryo II Tanto Blackwash Speed Assisted Opening Knife 1556TBW

$29.45
End Date: Sunday Nov-12-2017 12:51:35 PST
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KERSHAW Gray DIVIDEND Assisted Stonewash Straight Folding POCKET Knife! 1812GRY

$35.61
End Date: Wednesday Nov-15-2017 7:25:57 PST
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KERSHAW Gray Handle BLACKWASH LINK Assisted Straight Folding Knife! 1776GRYBW

$35.79
End Date: Wednesday Nov-1-2017 15:57:49 PDT
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Kershaw Link Tanto 1776TGRYBWX Assisted Opening with Flipper Pocket Knife

$30.00
End Date: Thursday Oct-19-2017 14:53:29 PDT
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SOG Sideswipe Assisted Open Lockback Pocket Knife SW1011-CP 7Cr15MoV Titanium

$41.25
End Date: Monday Nov-13-2017 9:33:25 PST
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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.