How To How do you define 'Tight' lock up?

jp9mm

jp9mm

Joined
Apr 1, 2019
Messages
544
I'm new to collecting knifes but i've owned maybe 10 different folders the past 20 years.
Most in the 20-50$ range but a couple 100+

All of the blades seemed to move some. mostly some level of side to side play, a couple with slight front to back movement.

I probably haven't handled enough knifes to understand this fully, so i'm asking others opinions.

What is your criteria for saying a folder has tight lock up?
 
There shouldn't be any side to side or up and down play in knives. That being said, it's fairly common in less expensive knives.

With some knives, it's a balance of getting the right smooth action at the cost of a less than solid lock up. Generally, as you loosen a pivot to get smooth or more free action, there can be the introduction of blade play in various direction.

Some designs can do both. Smooth and free action and still lock up tight as a bank vault. Others, not so much.
 
  • Like
Reactions: BBW
There is no definition other than what you find annoying. Each type of knife lock design has inherently different amounts of "play" in the "lock up". Each manufacturer has different amounts of "play" in their particular execution of a specific type of lock design. For example, one major manufacturer claims a little bit of play in a mid-lock lockback is "normal" others do not.
 
Most of my serious hard users have Tri-ad , Cold Steel back locks .

Ideally this type lock should feel like a fixed blade IMO .

I do have a couple that have the slightest bit of "rock" . Annoying but entirely functional . I expect they will wear in with time .
 
Rock Solid. No side to side, no up and down lock rock.
Many decent knives offer this, and some don't cost very much at all...$40 or so.
Chris Reeve knives, many Striders, most ZT's, nearly all Spyderco...
I am PUT OFF by any movement once in lockup...will NOT touch such a knife...
and if I get one, I'll dump it ASAP.
 
Depends on the price and the lock. I don't like side to side play, but I'll be the first to admit that even moderate amounts of side to side play make no difference in how a knife works as a knife.

Vertical play is generally bad but it depends on the price and design for me:
  • OTFs still cut things accurately and without issues despite having a small amount of blade play. I'd never be concerned with one closing on me or posing a safety risk.
  • Frame locks generally have a bit of lock flex when tested firmly for vertical play if the lock bar is contacting behind the pivot rather than below it (I consider this a poor design); this is off-putting for a $200-400 knife but not so much for a cheap knife. I'm generally okay with some tiny amount of lock flex as long as the lock geometry is good and the lock doesn't shift around on the blade tang.
  • Axis/compression/button lock knives generally have no play if well designed and if their parts are in tolerance, so I don't like to see it on these sorts of knives.
  • Triad locks can have a small amount of vertical play without causing safety issues. I'd prefer it not to be there but it's not a safety risk.
 
When I say tight lock up I mean a lock without play. Side to side play is not related to the lock. Up and down play depends on the lock. Most back locks have a little play. Some Axis locks have a little play. Liner/frame/compression locks shouldn't have any play.
 
I prefer to speak in terms of play, which I find to be more specific and clear than a term like “tight play”. Whenever possible, I try to use language which clearly communicates my meaning.
 
No side to side or back in forth play. Knives that have this don t have as tight tolerances as those that don t. Regardless of the type of lock. Side to side can often be corrected with pivot tightening. Back and forth play is a worse problem to correct.
Well made tools lock up tight.
 
Murphjd25 said:
I base everything how my CRK and Hinderers lock up. Like a bank vault!
Click to expand...
Funny, I don't particularly think CRK or Hinderer knives lock up all that tightly. Their locks can show flex even when the lock interface isn't slipping, just due to the geometry of how the lock engages the blade tang relative to the pivot.

I've had three Gen 6 Hinderers that had lock flex and an Umnumzaan that you could feel some movement in when checking for vertical play. They weren't defective; they just have a non-optimal placement for the lockbar.
 
No side-to-side and up-and-down play.

Some slip joint knives exhibit side-to-side play.
Some back lock knives exhibit up-and-down play.
 
You must log in or register to reply here.
Back
Top