I learned this about screws

[old man emu]

Do you get  annoyed when you are driving Phillips head screw and your screwdriver slips? Leaving aside the effect of the amount of torque you are applying, there's another reason why the screwdriver slips. It's because there are three types of holes in the heads of the screws we typically call Philips head.

 

I came across this video recently, and today I applied the information in it to select the correct driver tip to deal with screws in a tool made in England. After watching the video, can you tell me what type of screw I was dealing with?

 

 

[nomadpete]

The common type you are likely to find these days are a Chinese copy (not quite accurate) of the JIS  Japan Industry Standard that was developed to avoid royalties to Phillips (or to USA Posidriv which neither will fit)

 

 

 

Edited Friday at 10:56 AM by nomadpete