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monkey spanners
09-02-2013, 12:26 PM
Have any of you noticed when fitting Japanese air con that the philips head screws are often a poor fit in screwdrivers.

Maybe like me you put this down to poor quality screws soureced from china or such but it turns out that is not the case.

Way back when standards for screws were being decided upon the Japanese invented the JIS screw profile, it looks like a philips but is not designed to cam out when max torque is reach so will be damaged if the wrong driver is used.

Often the screws are identified by a small dot or dimple on the head, such as on the Saginomiya fan speed controls i noticed yesterday.

I have ordered a set of Jap drivers and will report back should anyone be interested :)

The same screws are used on Japanese motorbikes so similar problem would be found when working on these too.

install monkey
09-02-2013, 12:33 PM
i bought a set of screwdrivers with the fish and hook logo on 45 quid for a 7 peice set and the pozi sizes were pz2 and pz.75- so hence attacking a panasonic condenser - snapped the bugger - the 5 piece screwdriver set comes with a pz2 and pz1!- but thyre not monkeyproof- i just thought japanese manufacturers overtorqued their exported goods because lead based paint was banned!!!
wherever possible i use nutspinners

install monkey
09-02-2013, 12:35 PM
https://www.google.co.uk/search?q=jis+screws&hl=en&tbo=u&rlz=1C1OPRA_enGB510GB511&tbm=isch&source=univ&sa=X&ei=OUIWUZbMHaa_0QWcq4CQBw&ved=0CDkQsAQ&biw=1366&bih=653
pics

GHAZ
09-02-2013, 01:44 PM
Hi i damage 2 good strong philips screw drivers on daikin vrv just taking off back cover and then looked carefully at bolt head and it had 10.9 stamped pn it. And after that i used a 10mm socket

r.bartlett
09-02-2013, 02:32 PM
I only use Bahco screwdrivers and they never let me down:cool:..

Surprising the amount of 'engineers' who don't know the difference between Phillips and pozi screwheads though:eek:

install monkey
09-02-2013, 05:35 PM
https://www.google.co.uk/search?q=screw+head+types&hl=en&tbo=u&rlz=1C1OPRA_enGB510GB511&tbm=isch&source=univ&sa=X&ei=OogWUd2qB6KM0AXFjoGQBA&ved=0CEsQsAQ&biw=1366&bih=653
is that why sparkys use square head(robertson) screws because theyre too tight to buy a full set of screwys?

glenn1340
09-02-2013, 08:31 PM
How about the "Tamper proof" screws, like Torx but with the little tit in the middle if the recess. Thing is they`re not tamper proof if you can buy the bits to fit them so what`s the point?

Spencer.Guy
09-02-2013, 09:05 PM
How about the "Tamper proof" screws, like Torx but with the little tit in the middle if the recess. Thing is they`re not tamper proof if you can buy the bits to fit them so what`s the point?

Or break the pin out with a small screwdriver and use a normal torx