A little lesson in tools

[Xulfiqar]

When undoing toyota head bolts - please pay attention to the bolt head. I am making this thread after I was asked a similar question on email.

The question started as "why do toyota give such soft headbolts that their heads strip out".

The problem was user error. Toyota use a 12 point bi-hexagon female socket headbolt design. This is not interchangeable with the more known XZN design which also has 12 points but is actually called a triple square. The guy went out and bought an XZN drive and got himself into trouble. The double hex bits are a bit hard to source.

The triple square bit will fit in the bolt head but only the edges of the teeth will engage the bolt splines which will cause failure when torque is applied. To make it more clear a triple square socket has 3 squares super imposed on each other while a bi hexagon is 2 hexagons superimposed on each other.

The internal angles are different of the tools as a square has 90 degree corners while a hexagon has 60 degree corners.

Use the correct tool for the job - If you are using a mechanic then buy the proper tool yourself and have the mechanic use it. Don't let a simple tool make your day miserable.

[Dongskie]

@xulfiqar if I may add a photo of the head bolt for everyone's awareness:

The Correct socket tool:

[faiz.aslam.121]

Thanks for the heads up!

It would've been more informative to a noob like me, if you attached pictures, differentiating between 12 point bi-hexagon female socket headbolt design and XZN design which also has 12 points but is actually called a triple square
And, does most factory manuals state which kind of tools to use to work with?

[Xulfiqar]

The manual says to use a bi hexagon - but because it physically looks like an XZN people tend to think they are the same.

[Xulfiqar]

@Xulfiqar if I may add a photo of the head bolt for everyone's awareness:

The Correct socket tool:

This is the socket tool, Im talking about the bihexagon male bit socket - found in toyota 2NZ, 1ZZ, 2AZ, 2JZ etc.

This is the tool

The above is made by Snap-on. You can find other manufacturers too, Koken, Assenmacher, Elora etc.

[Dongskie]

Oh this one

[Xulfiqar]

yes that looks like a bi hexagon socket but your tool looks like its a triple square - the edges are pretty high,

[sr520]

Xulfiqar how do I get in contact with you, dont mean to thread jack but I dont see how to message you. Thanks

[supraman2jz]

Xulfiqar how do I get in contact with you, dont mean to thread jack but I dont see how to message you. Thanks

You can PM him if his inbox accepts any. Or add an @ before his name so it comes up in his mentions, like this @xulfiqar

[Umair93]

@xulfiqar can u plz tell me the callibration of nozzels(new) n injection pump of a 3c-turbo?..n what turbo to use on a 3c ct12 or ct20?..

[bike_junky]

yes that looks like a bi hexagon socket but your tool looks like its a triple square - the edges are pretty high,

Dear Xulfiqar. I didn't search the local markets but I could not find any 1/2" to 1/4" socket drive adapter on Amazon.
All I can find is 1/2" -> 3/8" -> 1/4" conversion path.
Can you please help me in finding 1/2" to 1/4" socket drive adapter on Amazon.
Do they exist or not?

[Xulfiqar]

1/2 to 1/4 inch drive?

I personally have not come across such and neither have had the need for this, infact the applied torque will immediately break the adapter or socket.

Its better to have a small toolset altogether.

[saboor73]

The manual says to use a bi hexagon - but because it physically looks like an XZN people tend to think they are the same.

what the worse could happen if we use XZN tool on bi hexagon bolts

[Xulfiqar]

what the worse could happen if we use XZN tool on bi hexagon bolts

you break the tool and in some cases round out the bolt itself - then bolt extractors are required.

[basic]

Worth digging.

When undoing toyota head bolts - please pay attention to the bolt head. I am making this thread after I was asked a similar question on email.

The question started as "why do toyota give such soft headbolts that their heads strip out".

The problem was user error. Toyota use a 12 point bi-hexagon female socket headbolt design. This is not interchangeable with the more known XZN design which also has 12 points but is actually called a triple square. The guy went out and bought an XZN drive and got himself into trouble. The double hex bits are a bit hard to source.

The triple square bit will fit in the bolt head but only the edges of the teeth will engage the bolt splines which will cause failure when torque is applied. To make it more clear a triple square socket has 3 squares super imposed on each other while a bi hexagon is 2 hexagons superimposed on each other.

The internal angles are different of the tools as a square has 90 degree corners while a hexagon has 60 degree corners.

Use the correct tool for the job - If you are using a mechanic then buy the proper tool yourself and have the mechanic use it. Don't let a simple tool make your day miserable.