A10 alloy head bolt thickness

[Nomad54]

Does anyone know what size washers are used on the alloy cylinder head a10s. Dragonfly are selling bolts with 1/16" thick washers but I was told they should be 1/8" thick. If anyone knows the correct thickness and where I can get them I would much appreciate it.
Tom

[trevinoz]

I use high tensile washers, they are thicker than 1/16" but I am not in the shed at the moment to measure them.

[limeyrob]

They are 02-2138 which is zinc plated 3/8 thick washer.  Feked list them as 0.09" which is near as damn it 3/32.
The BSAOC fastener list has them as 3/8 x 3/4 x 0.064 (about 1/16) which doesn't look right. I'd go with 3/32.
A 3/8 thick series (BS3410 Table 3) is 0.071"

[berger]

be careful of what you get regarding bolts , nuts and washers from the dragon , my 6 high tensile bolts for a flywheel and other bits ended up costing 60 odd quid and i could have bought the same crap they sent me in bags from B&Q for a fiver, needless to say they told me they had the proper 6 bolts and nuts with the part number for the flywheel but they hadn't then passed on the blame to a third party. the lot went back and i got a refund then used the good old brit made flywheel bolts and nuts i took out. the stuff they sent me made me SO ANGRY!!! rant over

[limeyrob]

I now try to re-use fasteners where I can. The old bolts are high quality and none of our applications torque them into the plastic range so they are all re-usable.  I had the same problem on a Land Rover diff, the original BSF bolts were at the top of the HT spec and the "OEM quality" replacements were at the bottom, about 25% difference.  In the end I found old stock, very frustrating.  Because there's not much BSF stuff about they pass off grade R as HT when its not.

[berger]

 Rob i like to re use and have loads of grandads and dads nuts and bolts plus loads from the coal board stores BSF BSW UNF UNC METRIC BA CEI and other stuff i borrowed years ago, this old stuff was well made and re useable not like the monkey metal of today you find on bikes and cars,  BUT when i ask for the part number of the bolts and nuts to be sent because those nuts on the crank bolts are bruised over with some sort of punch and they tell me they have them in stock i didn't expect 6 soft SET screws and 6 sloppy soft nuts a few soft washers and other such crap costing over 60 quid    i could have bought in placky bags at B&Q for a fiver , i will never use dragon again.

[BagONails]

Clearly you're still steaming Bergs but with good reason...

I've just put mine back together. The bolts and washers were stainless but at least 3mm thick washers I'd say.

Just went out and checked.

[Beeza]

ARP do a pack of 10, 5/16 X 3/4 X1/8 from memory I use them in all my alloy heads bikes, and on the salt bike they are replaced whenever the head goes back on, top quality too. Remember that you do need to spread the load when pulling down on an alloy head, so maximum OD (where the washer sits nicely in the machined out area is best)
Cheers Thomas