Is this common

[Stakeknife]

This is a Rough Ryder EZ lock back open trapper.

Half back spring, I’ve never seen this before, but there is alot I haven’t seen.

[Mumbleypeg]

Yes. Fairly common lockback mechanism. Often seen on lockback whittlers. Here’s one example https://www.allaboutpocketknives.com/kn ... 3#p1185843 More can be found by searching for “lockback whittler”.

Ken

[Stakeknife]

Thanks learn something new everyday

[Killgar]

They are often referred to as mid-locks.

Either because the lock release is midway down the handle, or because it's in the middle of the handle.

.

[Dinadan]

I have only seen it used on knives made in China or Japan. I have three whittlers with the half length springs and the lock in the middle of the back, pretty much the way your knife is constructed.

Rough Rider, Parker, and Klass

[QTCut5]

Very common...as seen on Case Cheetahs & Cheetah Cubs as well as the Case/Tony Bose Collaboration Lock Back Whittler.....all of which are USA made

[Mumbleypeg]

Very common...as seen on Case Cheetahs & Cheetah Cubs as well as the Case/Tony Bose Collaboration Lock Back Whittler.....all of which are USA made

Correct. It’s an old design. Not sure when/where it originated but it wouldn’t surprise me if it was Sheffield in the 1800s.

As Q said, probably one of the more popular is the Case x111-1/2 pattern (aka Cheetah), an old pattern dating back to the earliest days of Case. Parker had knives with the locking mechanism made in Japan. Frost is having the Chicoms make them for their Steel Warrior and other Frost-owned brand names.

Ken