How much loctite to use?

[Ocean1]

You two will know... assuming the torque setting given is for a clean dry fastener, how much effect (presumably it needs reduction) does the loctite have on that figure? 40% less?

You can calculate it. If you can get K values out of Loctite Ltd.

For heavy lubricants like anti-sieze the correct torque is half what you'd use dry. Loctite isn't a lubricant, though, so I typically drop it about 25%.

Bestt method is to actually measure the bolt length. The most practical alternative spec' is an old Catapiller trick: Torque to about 25% then turn a full 60 degrees. Very repeatable across different surface conditions.

Or you can use the electrician's method, tighten that fucker up 'till it strips an' back it off 1/4 turn.

[warewolf]

You two will know... assuming the torque setting given is for a clean dry fastener, how much effect (presumably it needs reduction) does the loctite have on that figure? 40% less?

No; for 243 keep it the same. There's a lot of friction between the bolt head and the surface which you aren't lubricating.

[warewolf]

"Blue" loctite is marginal for metal on metal. It will hold, but ideally use the medium-tough stuff (Purple). I use blue currently, after trialing purple for a year. Purple definitely holds, but can be harsh on soft metals and no good for threaded or thread through plastics.

Pretty sure you have it round the wrong way. Blue 243 is medium strength, purple is low strength. Blue is totally the thing for most chassis applications on a bike. And you don't want to put most anaerobic threadlockers anywhere near plastic as it causes stress fractures.

All you ever need to know about threadlockers and many other similar products is here: Loctite. The main respondent "dirty_sanchez" is a Loctite Factory Rep in the USA; he welcomes any and all questions, and really seems to know shit from clay.

[warewolf]

Prefer not to have to smash out more bolts, makes simple jobs a pain in the arse!

243 is serviceable with hand tools. You can also heat it to the release temp if you need to, very rough from memory is only 180 deg C or something - not much anyway.

The biggest problem with excessive amounts applied is the mess you have to clean up. Only the stuff that stays in the thread mating surfaces is actually doing any good. The rest is wasted $$$.

[The Lone Rider]

Just to add a bit more detail, as I happen to have pulled out a loctite write up

Loctite 243 Best Ever = Medium (new formulation they claim)
Loctite 263 Best Ever = High (new formulation)
Loctite 2422 = Medium grab up to 350C degrees
Loctite 2620 = High grab up to 350C


There is also:
Loctite 5770 High Temp thread sealant unto 280C (oil bung)
Loctite nickel based anti-sieze (good for helping to keep baffles removable)

They also have Loctite 249, which is medium strength, in a tape form.

[roadracingoldfart]

Its just like the word " Crescent " whats really meant is an adjustable wrench.
Why is it that people call thread lockers and retaining compounds by the brand name ?
If you want any specific answers i am a specialist in Loctites product range in both anearobic and cyanacrylate ranges , give me a holler if you wish.

To answer the original question its easy really. The thread clearance is generally the limiting factor to the ratio of compound actually used on the threaded area.A line up the thread is better to metre the contact dose. If you use too much though , it is possible that the surpluss will cure in a mass lump out of the thread area and damage the thread or strip when next withdrawn.

My personal 2 cents worth , 609 is a better thread locker in a m/cycle application due to the wet / hot and harsh vibration application.

Paul.

[LBD]

For heavy lubricants like anti-sieze the correct torque is half what you'd use dry. Loctite isn't a lubricant, though, so I typically drop it about 25%..

Rot....always lubricate threads and torque to 100% of recomendation...at the end of the day it is not the torque but the clamping force between the head of the bolt and the nut that is important. By not doing up to the correct torque you are asking for troubles

[jellywrestler]

thanks for the replies. Used 1 drop either side of the bolt placed 1/4 to 1/2 up the shaft and then tightened to torque spec. Its bloody runny stuff!

it shouldn't be runny
shake the bottle well first

[Ocean1]

Rot....always lubricate threads and torque to 100% of recomendation...

Fine. If the spec' is for a luricated install.

It's usually not.

...at the end of the day it is not the torque but the clamping force between the head of the bolt and the nut that is important.

Correct, but many torque spec' charts, (most?) are written for clean dry applications. In which case lubricating the thread and then tightening "to recomendation" will result in a much higher clamping force than the designer intended. If the bolt's application is close to its design limit it might also damage the thread. It will also often result in fasteners coming loose.

[LBD]

Fine. If the spec' is for a luricated install.

It's usually not.

Correct, but many torque spec' charts, (most?) are written for clean dry applications. In which case lubricating the thread and then tightening "to recomendation" will result in a much higher clamping force than the designer intended. If the bolt's application is close to its design limit it might also damage the thread. It will also often result in fasteners coming loose.

Sorry mate you are 100% unequivocally wrong...and seeing you mentioned Caterpillar....from the 789 manual...
"Clean and lightly lubricate fasteners before torqing to specification" There is no mention of adjusting down of torqe requirments for assembly with never seize.

A manufacturers specified torque setting is well within the bolts tensile strength...absolutely no where near a bolts design limit...

As for..... "If the spec' is for a luricated install. It's usually not."
30 years as a heavy equipment Caterpillar fitter I am yet to find a recomendation to assemble and torque up dry....The only dry exception is with new fastenings that are supplied coated with a dry lubricant...few and far between.

[warewolf]

30 years as a heavy equipment Caterpillar fitter I am yet to find a recomendation to assemble and torque up dry....

When Caterpillar start making bikes, you may find their default spec is dry like every other motorcycle manufacturer.

KTM uses lighter fasteners than is typical on Jap bikes. It's quite common for ham-fisted Jap enthusiasts to strip bolts left right and centre on their first KTM, until they learn to use a torque wrench. Triumph T4 Tigers also had some fasteners that would either strip or fall out, if not torqued to the correct value. Some so manufacturers do push their fasteners close to design limits. Perhaps not outright strength, but if the threads are ripped off they don't tend to hold much at all, in my experience.

[LBD]

KTM uses lighter fasteners than is typical on Jap bikes. It's quite common for ham-fisted Jap enthusiasts to strip bolts left right and centre on their first KTM, until they learn to use a torque wrench. Triumph T4 Tigers also had some fasteners that would either strip or fall out, if not torqued to the correct value. Some so manufacturers do push their fasteners close to design limits. Perhaps not outright strength, but if the threads are ripped off they don't tend to hold much at all, in my experience.

No argument there...torque the bolts to the manufacturers recomendation..the correct value as you put it....But not as Ocean says...subtract 25% of the manufactureres recomendation if you put lubricant on the thread....

I doubt you will find anyone (KTM?) recomending you assemble and torque up bolts without lubricant.
Lubricating the threads during assembly protects the threads...Dry threads in housings are a reason threads damage and strip.

[Ocean1]

I doubt you will find anyone (KTM?) recomending you assemble and torque up bolts without lubricant.

http://www.morbark.com/service/belttorque.pdf

[LBD]

http://www.morbark.com/service/belttorque.pdf

From a wood chipping machine manufacturer?

Note 1 on the chart states use the above value when a specified spec is not available...

What you recomended, is to reduce the equipment manufacturers spec if you lubricate the threads...two different things...the KTM manual will recomend you lubricate threads before torqueing to their specified value.

[warewolf]

No argument there...torque the bolts to the manufacturers recomendation..the correct value as you put it....But not as Ocean says...subtract 25% of the manufactureres recomendation if you put lubricant on the thread....

I doubt you will find anyone (KTM?) recomending you assemble and torque up bolts without lubricant.
Lubricating the threads during assembly protects the threads...Dry threads in housings are a reason threads damage and strip.

No, the only time KTM says to oil threads (and under the bolt head) is for cylinder head bolts. The rest of the time it's dry or with the specified Loctite (for the pedants; yes, the branded product as they OEM to KTM) or maybe some anti-seize compound. And I don't think it's just KTM (other manuals are out in the garage); I've never oiled threads and I'm an avid reader of instructions for getting the best results.

Yes, dry threads particularly into dissimilar metals are prone to galvanic(?) corrosion; a good way to stop this is to use threadlocker!