Breaking M20 bolt

[daleyd]

Molykote - we used to use it on furnace inspection door bolts at up to 1000 deg. Will check what it was exactly we used to use, but it goes on as a black paste and is ok up to 500 deg or so then provides dry lubrication up to something like 1200 deg.

 

[Agroshield]

...it needs to be able to survive heat treatment at just shy of 700c

It is not just surviving the warmth. I do not know under what atmosphere the parts are heat treated, but you do not want the lube to boil off and contaminate the HT oven, your parts or any other parts that are in the oven with your own. You also need to think of any interaction with the quenching medium. Take good advice off the HT people.

 

[addjunkie]

Copper slip, but if you do lube put it on the contact face of the head as well as the thread. I agree of the advice from the HT folk too.

but why are the threads mashed up?

 

[Hitch]

Bit of Swagelock silver goop on the new ones... after the female threads have been sorted.

 

[stuvy]

It is not just surviving the warmth. I do not know under what atmosphere the parts are heat treated, but you do not want the lube to boil off and contaminate the HT oven, your parts or any other parts that are in the oven with your own. You also need to think of any interaction with the quenching medium. Take good advice off the HT people.

Heat treated in a vacuum as per spec

Copper slip, but if you do lube put it on the contact face of the head as well as the thread. I agree of the advice from the HT folk too.

but why are the threads mashed up?

Blame the initial heat cycle then heat treatment

The 1” impact made sure they not only came out but the buckled bolts certainly didn’t help

 

[Trevorleach]

Yep all x15 came out with an 1” Milwaukee impact running a 5ah battery
With a hex 17mm x 1” square drive impact socket

My boss is gonna let me order one now

I have been told if you use the 8/9/12 ah batteries it makes the big guns better still.

 

[500e]

Some Bolts look as if screwed into blind holes that were not tapped deep enough

 

[chris pruteanu]

I have been told if you use the 8/9/12 ah batteries it makes the big guns better still.

I have a 2000 Nm 1/2” Milwaukee torque wrench and a 3/4” Milwaukee torque wrench, the 1/2” one would take really big bolts/nuts with 9Ah batteries ! I reckon the 1” was
Overkill as the 3/4” one does take off 46mm nuts on Iveco/Renault master rear axle nuts which are tighened as hell !
Friends of mine are running 1” Milwaukee impacts with 12Ah batteries and they have no problem with anything on Lorries/HGV’s !

 

[stuvy]

I have been told if you use the 8/9/12 ah batteries it makes the big guns better still.

I ordered 8ah but they sent 5ah so had to go with what they had

 

[stuvy]

Some Bolts look as if screwed into blind holes that were not tapped deep enough

Was a counter bored hole into a through hole

The heat bent the plate hence why they were stuck

 

[stuvy]

I have a 2000 Nm 1/2” Milwaukee torque wrench and a 3/4” Milwaukee torque wrench, the 1/2” one would take really big bolts/nuts with 9Ah batteries ! I reckon the 1” was
Overkill as the 3/4” one does take off 46mm nuts on Iveco/Renault master rear axle nuts which are tighened as hell !
Friends of mine are running 1” Milwaukee impacts with 12Ah batteries and they have no problem with anything on Lorries/HGV’s !

Thanks Chris the exact answer I was looking for

 

[Trevorleach]

I ordered 8ah but they sent 5ah so had to go with what they had

Try powertoolmate
Decent prices and fast delivery
Still worth checking around as they are not always the cheapest

 

[Trevorleach]

I have a 2000 Nm 1/2” Milwaukee torque wrench and a 3/4” Milwaukee torque wrench, the 1/2” one would take really big bolts/nuts with 9Ah batteries ! I reckon the 1” was
Overkill as the 3/4” one does take off 46mm nuts on Iveco/Renault master rear axle nuts which are tighened as hell !
Friends of mine are running 1” Milwaukee impacts with 12Ah batteries and they have no problem with anything on Lorries/HGV’s !

2000nm 1/2?

 

[Kram]

Heated in normal usage or heat treated once?
Can the parts be HT seperatly and bolted up after, or to avoid distortion?

Im not sure Id trust bog standard 12.9 bolts at those temps, probably needs some exotic inconel alloy or equally expensive

 

[chris pruteanu]

2000nm 1/2?

Yep…meant to say cordless impact gun, I hope I got across properly as English is not my 1st language!