...t25 t27 t30...

[kornbln]

Torx sizes go up in increments of fives after they hit T10 but between 25 and 30 we have 27, what's up with that odd size?

 

[MechanicNamedJohn]

Torx sizes go up in increments of fives after they hit T10 but between 25 and 30 we have 27, what's up with that odd size?

27 is for GM seat belt bolts. URRR wait, they are 47 never mind, but GM does need a 27 for something, I can't remember yet.

 

[Monte]

i think these golden things (dont know the english name) use torx 27 screws (for lathes)

 

[ngk22r]

Because 27 is in the middle of 25 and 30 equally.

 

[LittleFella]

I know that most of the fasteners on Stihl chainsaws and Buell motorcycles take a t27.

 

[handyvorb]

At Audi we use T27 on our transmission pan bolts off the top of my head. I'm sure I've used it and the T47 for more than one application.

 

[Fedwrench]

It's Chrysler's fault.

 

[jk47]

Harley's use T27

 

[kornbln]

Because 27 is in the middle of 25 and 30 equally.

So why are there no T17, T37, T47, etc

 

[Mike83]

Because 27 is in the middle of 25 and 30 equally.

???? Did you use a calculator to figure that?

 

[Mike83]

I think the point of his question is not what is the application but like kornbln said why no T37, etc. or why no T43 for that matter.

 

[Fedwrench]

I think the point of his question is not what is the application but like kornbln said why no T37, etc. or why no T43 for that matter.

As soon as Hansen makes a Torx bit rack with useless sizes, I'm sure at least one tool company will help you out.

 

[Skin]

I think the point of his question is not what is the application but like kornbln said why no T37, etc. or why no T43 for that matter.

one day the torx fastener machine operator came in drunk as a skunk and was suppose to produce 5 batches of 20,000 fasteners with a T30 drive. Only after they were produced and shipped did they realize the drunk ******* had produced some oddball size that neither the T30 or T25 would fit, hence the T27 was born. Thats the story i made up and i'm sticking to it.

 

[bmwpower]

Because, without T27, there would be a "large" gap in the torque range for the torx fasteners. T25 max torque is 19Nm, while T30 min torque is 31.1Nm. Hence, T27 was designed to fill that gap (22.5 to 26.9 Nm).

The other reason is the dimension, point to point - 4.99mm, almost 5mm exactly.

http://en.wikipedia.org/wiki/Torx

Just a guess.

 

[kornbln]

For some reason I thought the Torx size translated into some dimension of the bit but it doesnt seem that simple. How does the torx number relate to the dimension?

 

[Moose-LandTran]

I use T27 on VW-Audi diesel filter housings and not a whole lot else. Some other stuff, but i can't remember off-hand.

 

[bmwpower]

For some reason I thought the Torx size translated into some dimension of the bit but it doesnt seem that simple. How does the torx number relate to the dimension?

Anybody have access to these docs?

http://www.iso.org/iso/catalogue_detail.htm?csnumber=40257

 

[Moose-LandTran]

i think these golden things (dont know the english name) use torx 27 screws (for lathes)

Cutting inserts, i think..

 

[Monte]

yeah sounds good cutting insert