DB90
XS650 Addict
Anyone ever use a standard Grade 8 nut as a replacement?? Is there anything "special" about what the stock tappet lock nuts are made of? Seems to me plain old steel to me.
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Tappet nuts
- Thread starter DB90
- Start date
Grade 8 refers to it's strength. Not just hardness.... but shear and tension also.... elasticity....
Tappet nuts are alloyed and tempered with an emphasis on hardness.
Pretty much apples to oranges.
As to would it work? Possibly.
Not sure I'd risk the consequences if it won't.
Tappet nuts are alloyed and tempered with an emphasis on hardness.
Pretty much apples to oranges.
As to would it work? Possibly.
Not sure I'd risk the consequences if it won't.
DB90
XS650 Addict
Right. Grade 8 has a tensile strength of 150,000 ksi. I feel like that may be more than strong enough to withstand the forces it may be under.
I am no expert when it comes to bolts and nuts but grade 8 is standard for structural use.
Perhaps grade 10.9 or whatever it is may be better?
I am no expert when it comes to bolts and nuts but grade 8 is standard for structural use.
Perhaps grade 10.9 or whatever it is may be better?
Maybe I'm the wrong guy to answer... my background's in aviation, where substituting parts can lead to a world of shit.
So swapping a reciprocating nut that can wreak havoc on a cylinder head if it fails just goes against my grain.
If the question is do I think a G-8 nut is strong enough and will work, my initial thought is "probably."
My next though is it isn't worth rolling the dice... jus' get the correct nut.
Me thinks it's a potentially very expensive experiment. If you want to begin to research the topic, look for proof load properties of bolt classes. Then it also has to "live with" the valve stem and vice versa.....IDK
OK, I just ran a single cut file across a tappet nut. I expected it to skate off. It didn't... it bit into it pretty good. So they aren't as "hard" as I expected they were.
I'm still not gonna say yes though. I'll stick with my initial "possibly."
Seriously though, why take the chance?
I'm still not gonna say yes though. I'll stick with my initial "possibly."
Seriously though, why take the chance?
Btw.... that's a metric nut (I think). Grade 8 equivalent in metric would be a 10.8 nut.
DB90
XS650 Addict
I don't want to take the chance really. I was just curious because the tappet nut didn't seem to have anything special going on. At least from initial inspection. It had come off the Tappet and seems to have gotten squished a tiny bit by something in there (probably got caught by a cam lobe). I feel like if it were a hardened nut then it may not have gotten squished and chewed up as easily and without causing major damage to the cam, but I'm no expert.
I think you're right!
The plot thickens.... Popcorn?
So, as long as my ass is out here, I reckon it makes some sense that the nut is softer. The adjuster has to be something akin to bearing steel, so it would take a relatively soft nut to get proper stretch at the normal torque - otherwise it wouldn't stay tight.
A little help here, Jim...anyone?
A little help here, Jim...anyone?
Sounds about right.So, as long as my ass is out here, I reckon it makes some sense that the nut is softer. The adjuster has to be something akin to bearing steel, so it would take a relatively soft nut to get proper stretch at the normal torque - otherwise it wouldn't stay tight.
A little help here, Jim...anyone?
Grade 5 and locktite oghtadoit...
Nicole plated.
Nicole plated.
What about thread pitch, tolerances and nut height? Surely they aren't just standard metric coarse, with height 80% of thread outer diameter?
And who is Nicole?
I guess a chick into heavy metal
I’m really curious about this statement, kinda scary….
I erased this reply once cuz (do no harm).
But when snugging nuts (these especially) my last motion is a slight jerk. With threads, tightening, torque there is a thing known as cold welding. We've all experienced it, that slight catch/graunch as the nut gets tight, stops. The feel/sound is small areas of the sliding metal faces micro welding. This is part of what keeps a tight nut in place. Dunno, but I've never had a tappet nut loosen and I don't go gonzo on the wrench.
PS using an offset 6 point wrench here is more than a suggestion. Finish with a slight bump on the wrench.
That is all.
PPS Nichole is a honey.
But when snugging nuts (these especially) my last motion is a slight jerk. With threads, tightening, torque there is a thing known as cold welding. We've all experienced it, that slight catch/graunch as the nut gets tight, stops. The feel/sound is small areas of the sliding metal faces micro welding. This is part of what keeps a tight nut in place. Dunno, but I've never had a tappet nut loosen and I don't go gonzo on the wrench.
PS using an offset 6 point wrench here is more than a suggestion. Finish with a slight bump on the wrench.
That is all.
PPS Nichole is a honey.
DB90
XS650 Addict
What do you mean?
That's usually how I tighten them up too. I have absolutely no idea how the nut had come off. This is a new build and I definitely should have gone through more thoroughly and double checked everything. Just got excited to fire her up I guess haha. The second it started I knew something was not right because the ticking was SO LOUD haha.
DB90
XS650 Addict
Btw anyone wanna sell me a couple tappet nuts?
