Stihl with aluminum screws?

[Ricardo Oscar Fiegel]

Good afternoon, I see this together with these Stihl. 1142 007 1001 bearings, there are some screws that appear to be made of light alloy, aluminum? These screws are intended for the MS 462, which appear to be to close the crankshaft block, my question is if they also come in the upper part of the engine, in the cylinder.

 

[pioneerguy600]

What makes you think they are aluminum? I have yet to see any here, there are silvery plated steel ones as replacements for the former brass/ gold colored ones.

 

[ZeroJunk]

Yeah, one of those crazy internet conspiracy deals I guess... Everything about it is pointless.

 

[cscltd]

Stihl is using 1 use only aluminum screws for some of the crankcase halves now. So some items will come with new screws as you can’t reuse them. They are torqued to a certain number and then tightened 90*
You can use reg steel screws in place if you prefer as the aluminum was for weight reduction

 

[ZeroJunk]

I guess the question would be why ? Aluminum is certainly not cheaper.
Dissimilar metals seizing ? Maybe. But, hasn't bothered them for the past 50 years.

 

[Ricardo Oscar Fiegel]

What makes you think they are aluminum? I have yet to see any here, there are silvery plated steel ones as replacements for the former brass/ gold colored ones.

What makes you think they are aluminum? I have yet to see any here, there are silvery plated steel ones as replacements for the former brass/ gold colored ones.

I do know the steel ones, but the ones I mentioned are certainly not made of steel, they are made of a light alloy and very similar to aluminum.

 

[Ricardo Oscar Fiegel]

Stihl is using 1 use only aluminum screws for some of the crankcase halves now. So some items will come with new screws as you can’t reuse them. They are torqued to a certain number and then tightened 90*
You can use reg steel screws in place if you prefer as the aluminum was for weight reduction

That's exactly what I heard

 

[Vintage Engine Repairs]

the aluminum was for weight reduction

Stihl have gone too far with weight saving at the cost of strength and longevity on their modern saws. This is now just bordering on the absurd.

 

[Mad Professor]

See if a magnet sticks

 

[J D]

I suspect it's just as much about redundancy... how many shops are going to even consider splitting a case to do work if there's a 50/50 chance a screw will snap & be a pita to get out

 

[epo]

Aluminum single-use screws.





Specified torque 3 Nm (27 lbf.-in.)!

 

[epo]

See if a magnet sticks

Stainless steels can be non-(ferro)magnetic. E.g. 316, from which screws are also made. It can be classified as paramagnetic (like aluminum) . Here the density (mass or weight of the screw) will be more revealing.

 

[Vintage Engine Repairs]

Aluminum single-use screws.

View attachment 1197316

View attachment 1197315

Specified torque 3 Nm (27 lbf.-in.)!

View attachment 1197314

I was hoping it was going to be a misunderstanding. This is as ridiculous as using a paperweight as a ships anchor to save shipping costs….

 

[freeasaburt]

What the hell, pretty ridiculous indeed.
Could it be that the alloy the case halves are made of, was changed too? So steel screws could damage them, when tightened too firmly? Just a thought...

 

[pioneerguy600]

It seems this is just another step towards throwaway machines, if these screws become known for breaking off during removal no shop will want to be bothered at repair, just toss the parts and replace or buy a new complete saw!

 

[cscltd]

Cars also use these screws on parts on engines. Some belt idlers are held on with them.
I was always told the #1 cause of chainsaw accidents was operator fatigue. So a lighter saw would reduce that as minute as it seems.
I always say an engineer will get laid off unless he changes something or tries to reinvent something that works!

 

[Vintage Engine Repairs]

It seems this is just another step towards throwaway machines, if these screws become known for breaking off during removal no shop will want to be bothered at repair, just toss the parts and replace or buy a new complete saw!

Couldn’t agree more, it’s utter insanity they’re using them. They’ll snap and cause more problem, guaranteed

 

[altatim]

I honestly don't see the issue with using aluminum screws, if you look at the tensile strengths of materials, a grade 8 bolt (standard metric) has about 900MPa yield strength, 7075 AL has about 500MPa yield strength and 6061 AL has about 260MPa yield. Compared to even the best cast magnesium alloys that only provide about 160-200 MPa yield. So as long as they are properly installed they will not yield until after the magnesium threads have been pulled out (assuming pure tension). You can still obviously break the aluminum bolts from removing and installing multiple times due to fatigue, but they shouldn't fail without cause.

 

[Ricardo Oscar Fiegel]

Aluminum single-use screws.

View attachment 1197316

View attachment 1197315

Specified torque 3 Nm (27 lbf.-in.)!

View attachment 1197314

Good logic, I liked it, and about the tightening, 3Nm plus 90º. Is that right?

 

[epo]

Good logic, I liked it, and about the tightening, 3Nm plus 90º. Is that right?

Yes, Stihl recommends tightening these screws this way.