For this last thing: mathematics is an important tool for understanding the world – it is used in physics, mechanics, even chemistry.

JIS : JIS Ph1, JIS Ph2, JIS Ph3 ; Phillips : Ph0, Ph1, Ph2 (x2), Ph3 ; Plat : 3, 4, 5, 6, 7 mm ; PzDrive : Pz1 (x2), Pz2 (x3), Pz3 (x2) ; Hexagonal : 2, 2,5, 3, 4, 5, 6 mm ; Étoile* : T10, T15, T20, T25, T30, T40. Based on my experience, I ‘m confident the cross-point screws used on Shimano components have a JIS standard cross-point head. At the same time, the screwdrivers that work well with JIS screws (Shimano and Japanese motorcycles in particular), don’t slip any easier out of Phillips screws (as far as I could tell – they work better with those too). No other European screwdriver I have used including Wera kraftform, Wiha softfinish, Witte fit as well as true JIS drivers.What I do know, from practice, is that most “Phillips” screwdrivers, even when brand new, slip relatively easily out of cross-headed screws on my Yamaha and on Shimano derailleurs, while very few screwdrivers don’t.

I get a chuckle when comparing these screwdrivers tips and a similar comparison of the newer styles of open end wrenches currently available.Pound Through JIS Screwdriver Set If you've got a tight JIS screw, insert one of these screwdrivers into the head and give the top of the screwdriver a good sharp tap with a hammer and you'll find that you should be able to undo it. I've sold hundreds of TOPTUL screwdrivers built to the DIN 5260 specification, primarily to motorcycle people as they are the ones that have the most problems since their screws are torqued the tightest, and they have all LOVED them. Although the screw heads may look like regular Phillips head screws, a normal screwdriver never seems to fit correctly. My understanding is that the ISO 8764 standard tries to unify the Phillips and JIS drivers into one universal driver that is supposed to work equally well with both types of screws.