Thread Pitch

[Big G]

So just a quick question. I am off to get some bolts to start the AC installation on the Princess' rolla and just want to confirm that the bolts used by Toyota are 1.25mm thread pitch. What would be the best type of bolt to use for attaching the AC bracket to the block.

[Banjo]

Hi Graeme,

                   I believe the AC bracket bolts are probably exactly the same as the bolts used to attach the alternator bracket on the opposite side of the block.

I'll measure them in the morning & let you know.  I've probably got a few floating around, that I can let you have.

Cheers Banjo

[Banjo]

Hi Graeme,

                    The alternator / AC bracket mounting bolts are a 10mm dia. bolt 25mm long.  Comes off with a 14mm spanner. You can get them easily in the little packets of  2 or 4 off at Supercheap or AutoOne, on those revolving stands, of little bits & pieces.   If they haven't got the exact length you require, just buy a slightly longer one, & cut it to length.

If you still have trouble finding the right ones, give me a yell, & I'll dig a couple out of my box of nuts & bolts for you.

Cheers Banjo

[Big G]

Hey Banjo

I have a list of the lengths and size (10mm) from the install manual which has been super handy to work from. When I was at the Happiest Place On Earth (Bunnings) I grabbed some M10 bolts "with a metric thread" to get me started only to find the pitch was 1.5 and it seems after checking with my thread gauge that that our honourable friends at Toyota enjoy using a 1.25 pitch. So I don't know how  available over the counter at the auto shops they will be. I am going to check at some bolt shops today. If I get desperate for some I will let you know. Thanks for your help. 

 

[Banjo]

Hi Graeme,

                   The ones at the auto shop are the right thread.  I've purchased them there previously, for odd ones I've need for my Rolla, & they have always been the right 1.25 thread pitch.

Cheers Banjo

[Hiro Protagonist]

On 9/22/2017 at 8:17 AM, Big G said:

Hey Banjo

I have a list of the lengths and size (10mm) from the install manual which has been super handy to work from. When I was at the Happiest Place On Earth (Bunnings) I grabbed some M10 bolts "with a metric thread" to get me started only to find the pitch was 1.5 and it seems after checking with my thread gauge that that our honourable friends at Toyota enjoy using a 1.25 pitch. So I don't know how  available over the counter at the auto shops they will be. I am going to check at some bolt shops today. If I get desperate for some I will let you know. Thanks for your help. 

 

You should always check thread pitch when buying fasteners.  A lot of automotive stuff will be Fine thread, whereas most of the generic building products (like what the Big Green Box stocks) will be Coarse.  Another thing to be careful of is that for a given diameter there will only ever be one Coarse thread size, but often multiple Fine sizes (so the word on its own isn't enough).  M12 is normally 1.75mm (Coarse) but can be 1.5mm or 1.25mm (Fine)

[rebuilder86]

to add to all this, in my experience it works like this.

bunnings is useless for automotive threads unless u are simply buying bolt and nut as a package or are dealing with a smaller size thread, for qhich only standard thread exists.

auto threads are usually broken into 3 categories, fine metric . super fine metric and sometimes even UNF for older large 4WDs and commercials.

 

you will find standard metric threads places that arent safety related like, carby - manifold bolts, door hinges, bodywork ( although most body bolts are too small for there to even be a fine pitch version) and sometimes mounting bolts in and around engine bay.

anything related to steering, holding the drivedrain to the chassis or safety like seats and seatbelts, are usually extra fine or unc-unf, damn americans.

everything else is usually the finer of the metric thread pitches available for the bolt diameter in question.

i find myself picking up the thread taps from the "fine" side of my tap and die kit much more often than the std side.

you can fine a list of these fine threads here.

http://www.autospeed.com/cms/article.html?&title=All-You-Need-to-Know-About-Nuts-Bolts&A=112208