Helpful Hint

riptragle1953

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Every single threaded stainless steel fitting ..... especially bolts..... should be burnished with a light gauge rotary wire wheel to avoid the dreaded stainless seizure. However, if the threads were formed by compression (rolled) then there is no worry.
Wearing good side protected safety glasses is a must.... as I learned from my own painful experience when one of those fast spinning light steel wires broke loose and got me from the side.... at that rpm they can bounce and change direction at terrific speed.
 
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riptragle1953

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Yes.... holding the nut firmly with a tool and using assorted gun bore cleaning brushes.
I use Loctite #242 and #271...... the idea is not to make the bolt slippery as it will be made tight and you usually wish it to stay that way.
The burnishing helps the nut and bolt NOT seize on it's way to tight or off the machine. If a s/s nut and bolt do seize..... it's hacksaw time!
 

Big Sid

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Nice stuff Rip . I had a SS nut on a SS bolt just turned on by finger alone seize up solid , it's like peanut butter and flows together . Sid .
 

riptragle1953

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Sid, s/s hardware is knocked out at a rapid pace with a screw machine. The chances are even the cutting tooling hasn't been sharpened in a coons age. Screws can bee full of burs just waiting to meet up with another one. What the hell, the company saved money....
which is all that really counts. There is well made s/s hardware from big time suppliers who can supply work to military specs...... but I can't afford that..... so it off to the wire wheel!!!!!
 

vince998

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I believe it´s called Galling?
Rolled to rolled or cut to cut threads work well. the problem starts when you mix a rolled with a cut thread. the rolled thread has a radius at the crest and the root of the thread. A cut thread should also have a small radius, but to different dimensions to a rolled/formed thread. The cut peak will sieze (gall) in a rolled root. (this applies to all materials)
Industrial produced nuts and bolts all have a tolerance range to maximise tool usage/life. A screw or bolt produced on old tooling (therefore at the upper range of its tolerance and larger in dia) has minimum clearance in a nut also produced on old tooling (smaller internal Dia)
Allways use matched taps and dies when cutting external/internal threads, as to close a flank tolerance will also cause this. If in doubt as to the nut/bolt finishing tolerance, run your cutters down/over them first.
I have tried fitting cylinder studs (cut thread) to new crankcases (formed threads as common practice (and stronger than cut threads in aluminium) in CNC production nowdays) in the past. The only way to get them in was to chase the case threads with a tap.
 

greg brillus

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Stainless may seem practical and look the part longer than original hard ware, it is certainly not user friendly. A lot in the aviation game use it in place of cad plated screws to hold sheet metal covers and fairings in place, but they are generally much softer ( the philips head slot just chews out easily) and also its electrolitic properties are way bad on anything alloy.....but it does look good though....just don't use on anything structural......Just my thoughts.......Greg.
 

riptragle1953

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The camming of out tooling is common with factory made s/s parts.... they alloy it with lead so it's easier to machine
Rolled threads are not found on common s/s hardware but mostly special parts.... but what you say is perfectly true.
I need to write a piece on screwdrivers and the importance of using the right one and sharpening and fitting the tool for the screw.... this his the most common cause of buggered screws.
 

chankly bore

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Just a quick addition as fasteners are a bugbear of mine. All the currently supplied cheesehead screws and bolts are WRONG. They are made to B.S. 450 of 1958 which supersedes and departs from B.S. 450 of 1932 obtaining when most H.R.D's and all Vincents were produced. Just a little aside to keep the restorers humble. Don't even start me on nuts, bolts and washers. I scrounge mine off old British car wrecks and get them re-plated. At least, as Rip says, they are made of good steel-"R" grade 45 ton, "T" grade 55 ton minimum and the washers are FLAT.
 
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