Metric equivalent to AN bolts?

[LarryWinkelman]

Is there such a thing as a metric "AN" style bolt (unthreaded shank, probably 8.8 strength, 2 or 2.5 mm incremental grip length)? If so, where to buy?

[Thomas Wirtz]

Try the Bolt Depot

https://boltdepot.com/Metric_hex_bolts

[kea]

Try Metrics Unlimited in Warren, MI

[EYERACE]

Thank you for the link Tom
rough numbers.......
(grade 5, sizes over 1 inch to1.5 inch) 105,000 psi = 724 Megapascals (almost equivalent Metric A-2 or A-4 Stainless),
(grade 5, 1/4 to 1 inch) 120,000 psi = 827 MPa (almost equivalent Metric Class 8.8)
(grade 8) 150,000 psi = 1,034 MPa (almost equivalent Metric Class 10.9)

A lot of AN bolts have a psi in the neighborhood of 125,000 psi. OK all you Engineers out there do correct this humble Eye Doc.....cuz
remember, Eye know nothing..........and neither does Sgt. Schultz

[tlracer]

There's a good overview of metric fasteners here:

https://arunfasteners.co.uk/stock-ra...ric-hex-bolts/

Also a useful chart here:

https://www.mudgefasteners.com/news/...tric-fasteners

There are three grades - 8.8, 10.9 & 12.9:

8.8 is the equivalent of imperial Grade 5
10.9 is the equivalent of Grade 8
12.9 is the equivalent of L9 (which I'd never heard of until I started looking!)

Both Unbrako and Holo-Krome make metric bolts that are decent quality. The most common manufacturer (certainly here in the UK) seems to be Fang Sheng, which are marked 'YFS' on the head. From experience I've had some very poor quality ones (bad thread rolling, unacceptably open structure to the base metal, etc.) that I've returned to the supplier, so I avoid them now!

[toolo4sno]

Is there such a thing as a metric "AN" style bolt (unthreaded shank, probably 8.8 strength, 2 or 2.5 mm incremental grip length)? If so, where to buy?

I don't think there is a metric AN. Although in Redford there is Tradesman Fastener & Tool. They may know.

[EYERACE]

A cadmium plated metric bolt with a very high MPa (think 860 or higher) would roughly be your equivalent of AN (which have a psi of 125,000 or higher)

[Hardingfv32]

Interesting topic. From what I can find it seems that Airbus uses the Imperial AN system on their air frame and all major sub-systems.

Brian

[Rick Kirchner]

This is about more than strength - its about having the proper threaded length, in small enough increments to use a stack of washers and a nut to get the proper thread engagement and save weight when using a couple thousand of them. Its about having control of all the processes, including the plating processes. its about the specifics of finishing the thread at the shank of the bolt so it doesn't break there, as well as the way the head is formed.

I'm surprised Airbus uses imperial, as I thought the EU had laws about those things. Wonder what the rest of the European defense sector uses - tanks, electronic equipment, etc.

[LarryWinkelman]

Since my car has some metric fasteners I would like to use full shank bolts so that the load isn't through the threads, and so the threads don't act as a mill to elongate the mounting holes. I have yet to find such a creature, although buying extra long bolts and cutting of some of the threaded portion might work in a few places.

[kea]

I'm surprised Airbus uses imperial, as I thought the EU had laws about those things..

I'm not.
I've always said, can you imagine the issue if someone mistakenly used a metric fastener into/through a part designed for an MS,AN type..Maybe that's how a few planes have been loosing wheels recently (probably not the case) !

[Dave Harmison]

I’d say it’s more a function of the size of the US Defense budget. The 800 lb gorilla gets to pick the bananas that are available.

Now, if Boeing keeps doing the Max and stranding astronauts with Starlink, maybe Airbus will call the shots.