We use the term "Fixing" as anything which holds a pcb to a carrier.

It might seem silly to you to have a design philosophy for a bit of plastic holding a pcb in a carrier.
Then again you probably don't have to operate them, for an eight or twelve-hour shift, every day,
for months on end. The people who use them need someone to have a design philosophy, so here it is.

Be easy and obvious to operate - all of our fixings can be used blind.
Have fixed stops - so that you know without looking that the fixing is on.
Work the same way all the time - Clockwise ON , Counter Clockwise OFF.
Be cool to touch - made from thermally insulating material.
Not gum up - important in these days of no clean flux.

45° angled handle As far as we know we are the only company in the world who puts their fixing handle at 45°.
This helps the operator not to hit any upstanding components, and allows a flick rather than a twisting type of action.
(Large companies will not allow any twisting action - for fear of development of Repetative Strain Injuries.)

Rounded lift / sharp edge This allows the fixing to turn easily on but to grip the maximum area.

Common Metalwork -This allows us to make the greatest possible saving whilst still allowing cross retrofit
(Pingu/Rockhopper) and higher quality.