I did not test it intentionally but I remember..
Spyderco Tenacious and Military Linerlock falling on concrete from approx. 1m - blade 1/8 open to half open
Spyderco Tenacious and Military falling on the grass/leaves from approx. 1m - blade 1/8 open or closed, depending on impact
Spyderco Military falling on wooden floor from 1m - half open
Cold Steel Recon 1 Clip Point falling on grass/leaves - closed
Cold Steel Mini Lawman falling on anything - closed
Spyderco Tenacious and Military Linerlock falling on concrete from approx. 1m - blade 1/8 open to half open
Spyderco Tenacious and Military falling on the grass/leaves from approx. 1m - blade 1/8 open or closed, depending on impact
Spyderco Military falling on wooden floor from 1m - half open
Cold Steel Recon 1 Clip Point falling on grass/leaves - closed
Cold Steel Mini Lawman falling on anything - closed