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Why not to use just any SS studs
Thread galling seems to be the most prevalent with fasteners made of stainless steel, aluminum, titanium, and other alloys which self-generate an oxide surface film for corrosion protection. During fastener tightening, as pressure builds between the contacting and sliding thread surfaces, protective oxides are broken, possibly wiped off, and interface metal high points shear or lock together. This cumulative clogging-shearing-locking action causes increasing adhesion. In the extreme, galling leads to seizing - the actual freezing together of the threads. If tightening is continued, the fastener can be twisted off or its threads ripped out.
Carpenter Technologies, the fastener industry's largest supplier of stainless steel raw material, refers to this type of galling in their technical guide as "cold welding." Anyone who has seen a bolt and nut with this problem understands the graphic nature of this description.
The IFI and Carpenter Technologies give three suggestions for dealing with the problem of thread galling in the use of stainless steel fasteners:
1. Slowing down the installation RPM speed will frequently reduce, or sometimes solve completely, the problem. As the installation RPM increases, the heat generated during tightening increases. As the heat increases, so does the tendency for the occurrence of thread galling.
2. Lubricating the internal and/or external threads frequently eliminates thread galling. The suggested lubricants should contain substantial amounts of molybdenum disulfide (moly), graphite, mica, or talc. Some proprietary, extreme pressure waxes may also be effective. You must be aware of the end use of the fasteners before settling on a lubricant. Stainless steel is frequently used in food related applications, which may make some lubricants unacceptable. Lubricants can be applied at the point of assembly or pre-applied as a batch process similar to plating. Several chemical companies offer anti-galling lubricants. One such source, EM Corporation, suggests their Permaslik¨ RAC product for use at the point of assembly. They suggest Everlube¨ 620C for batch, pre-applying to stainless steel fasteners.
3. Using different stainless alloy grades for the bolt and the nut reduces galling. The key here is the mating of materials having different hardnesses. If one of the components is 316 and the other is 304 they're less likely to gall than if they're both of the same alloy grade. This is because different alloys work-harden at different rates.
Another factor affecting thread galling in stainless steel fastener applications is thread roughness. The rougher the thread flanks, the greater the likelihood galling will occur. In an application where the bolt is galling with the internal thread, the bolt is usually presumed to be at fault, because it is the breaking component. Generally, it is the internal thread that is causing the problem instead of the bolt. This is because most bolt threads are smoother than most nut threads. Bolt threads are generally rolled, therefore, their thread flanks are relatively smooth. Internal threads are always cut, producing rougher thread flanks than those of the bolts they are mating with. The reason galling problems are inconsistent is probably due largely to the inconsistencies in the tapping operation. Rougher than normal internal threads may be the result of the use of dull taps or the tapping may have been done at an inappropriately high RPM.
BUT
I searched a little and read a lot and heres some info on high tensile strength SS studs. 
ARP manufactures a variety of premium grade bolt and stud kits to
facilitate installation of exhaust headers including the popular stainless stud
kit with 12-point nuts. The Stainless 300 material is not affected by corrosion
or extreme heat, making it ideal for the application. What’s more, the
compact 12-point nut lets you easily slip a socket close to the pipe. Each ARP
accessory stud or bolt kit includes the specific number of parts for your application,
plus premium-quality washers and hex or 12-point nuts, as required.
Studs are manufactured with a unique nut-starter nose that helps prevent
cross-threading. Studs and bolts come either black oxide chrome moly or
Stainless 300. Both are nominally rated at 170,000 psi tensile strength;
substantially stronger than Grade 8 hardware. Specially drilled “NASCAR”
models are available for those who wish to safety wire their header bolts to
Special “NASCAR” model prevent loosening
Thanxs to Our friend Mathh for this info, from this previous post, on this topic.
{ 10-01-2008, 05:30 AM
Mathh
XStremely XSive Join Date: Nov 2006
Location: Beek, Netherlands
Posts: 291
Thanks to Miti from the UK forum, there are two types :
part# 95611-08625-00;
Internal thread - 16 mm long , external thread - 18 mm long, overall length - 41 mm (centre shank - 7 mm)
part# 95621-08615-00 (same as 3H3);
Internal thread - 15 mm long, external thread - 12 mm long, overall length - 31 mm (centre shank - 4 mm)}
The longer studs @ 41mm are approx. 1 19/32'' which the 1.5'' will work for the Standards.
The shorter studs @ 31mm are approx. 1 7/32'' which the 1.25'' will work for the Specials.
http://www.summitracing.com/parts/ARP-400-8012/ (for Standards)
http://www.summitracing.com/parts/ARP-400-8011/ (for Specials)
A little pricey @ $ 10.00 a peice, but another option.
Thread galling seems to be the most prevalent with fasteners made of stainless steel, aluminum, titanium, and other alloys which self-generate an oxide surface film for corrosion protection. During fastener tightening, as pressure builds between the contacting and sliding thread surfaces, protective oxides are broken, possibly wiped off, and interface metal high points shear or lock together. This cumulative clogging-shearing-locking action causes increasing adhesion. In the extreme, galling leads to seizing - the actual freezing together of the threads. If tightening is continued, the fastener can be twisted off or its threads ripped out.
Carpenter Technologies, the fastener industry's largest supplier of stainless steel raw material, refers to this type of galling in their technical guide as "cold welding." Anyone who has seen a bolt and nut with this problem understands the graphic nature of this description.
The IFI and Carpenter Technologies give three suggestions for dealing with the problem of thread galling in the use of stainless steel fasteners:
1. Slowing down the installation RPM speed will frequently reduce, or sometimes solve completely, the problem. As the installation RPM increases, the heat generated during tightening increases. As the heat increases, so does the tendency for the occurrence of thread galling.
2. Lubricating the internal and/or external threads frequently eliminates thread galling. The suggested lubricants should contain substantial amounts of molybdenum disulfide (moly), graphite, mica, or talc. Some proprietary, extreme pressure waxes may also be effective. You must be aware of the end use of the fasteners before settling on a lubricant. Stainless steel is frequently used in food related applications, which may make some lubricants unacceptable. Lubricants can be applied at the point of assembly or pre-applied as a batch process similar to plating. Several chemical companies offer anti-galling lubricants. One such source, EM Corporation, suggests their Permaslik¨ RAC product for use at the point of assembly. They suggest Everlube¨ 620C for batch, pre-applying to stainless steel fasteners.
3. Using different stainless alloy grades for the bolt and the nut reduces galling. The key here is the mating of materials having different hardnesses. If one of the components is 316 and the other is 304 they're less likely to gall than if they're both of the same alloy grade. This is because different alloys work-harden at different rates.
Another factor affecting thread galling in stainless steel fastener applications is thread roughness. The rougher the thread flanks, the greater the likelihood galling will occur. In an application where the bolt is galling with the internal thread, the bolt is usually presumed to be at fault, because it is the breaking component. Generally, it is the internal thread that is causing the problem instead of the bolt. This is because most bolt threads are smoother than most nut threads. Bolt threads are generally rolled, therefore, their thread flanks are relatively smooth. Internal threads are always cut, producing rougher thread flanks than those of the bolts they are mating with. The reason galling problems are inconsistent is probably due largely to the inconsistencies in the tapping operation. Rougher than normal internal threads may be the result of the use of dull taps or the tapping may have been done at an inappropriately high RPM.
BUT
I searched a little and read a lot and heres some info on high tensile strength SS studs. ARP manufactures a variety of premium grade bolt and stud kits to
facilitate installation of exhaust headers including the popular stainless stud
kit with 12-point nuts. The Stainless 300 material is not affected by corrosion
or extreme heat, making it ideal for the application. What’s more, the
compact 12-point nut lets you easily slip a socket close to the pipe. Each ARP
accessory stud or bolt kit includes the specific number of parts for your application,
plus premium-quality washers and hex or 12-point nuts, as required.
Studs are manufactured with a unique nut-starter nose that helps prevent
cross-threading. Studs and bolts come either black oxide chrome moly or
Stainless 300. Both are nominally rated at 170,000 psi tensile strength;
substantially stronger than Grade 8 hardware. Specially drilled “NASCAR”
models are available for those who wish to safety wire their header bolts to
Special “NASCAR” model prevent loosening
Thanxs to Our friend Mathh for this info, from this previous post, on this topic.
{ 10-01-2008, 05:30 AM
Mathh
XStremely XSive Join Date: Nov 2006
Location: Beek, Netherlands
Posts: 291
Thanks to Miti from the UK forum, there are two types :
part# 95611-08625-00;
Internal thread - 16 mm long , external thread - 18 mm long, overall length - 41 mm (centre shank - 7 mm)
part# 95621-08615-00 (same as 3H3);
Internal thread - 15 mm long, external thread - 12 mm long, overall length - 31 mm (centre shank - 4 mm)}
The longer studs @ 41mm are approx. 1 19/32'' which the 1.5'' will work for the Standards.
The shorter studs @ 31mm are approx. 1 7/32'' which the 1.25'' will work for the Specials.
http://www.summitracing.com/parts/ARP-400-8012/ (for Standards)
http://www.summitracing.com/parts/ARP-400-8011/ (for Specials)
A little pricey @ $ 10.00 a peice, but another option.
)
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