High Strength Bolts 1

[Sid89]

Hello Everyone. I am new here.

I need to know what is the Aerospace grade bolting? Is there any material specification for such boltings like B7 or B8, etc.?

 

[Sparweb]

Hi
You're new to fastener standards, too, then.

In aerospace, ASME bolt specifications are inadequate for the number and criticality of many joint fastenings needed.
We use fasteners mostly from the NAS specification, which is published by the AIA (Aerospace Industries Association).
Since there are thousands of NAS spec's now, it's hard to be too specific with the question you've started with.
You can start looking up some identifications of these types at IHS.
A little easier to browse is the Genuine Aircraft Hardware catalog.

What are you building?

http://www.sparweb.ca

 

[Sid89]

We intend to use aerospace grade bolting on a 3 piece ball valve that will be used to control the flow of rocket fuel. What will be the best grade material for this type of application?

 

[Sparweb]

Woah.
You don't seriously think that the bolt selection can be done independently of the valve design do you?
Liquid rocket fuel is volatile and flammable. The fact that you didn't bother to mention this in your first post sends me the message that you aren't taking this seriously enough.
I recommend you get someone with actual high-power rocketry experience to assist you.

https://www.nar.org/high-power-rocketry-info/

http://www.sparweb.ca

 

[rb1957]

Sid89,

where the heck are you ? "rocket fuel" makes me think of ITAR etc, so we need to be careful discussing this.

I think there's much to be gained looking at what you can find around on the "interwebs". I would think you need something like a stainless steel 160-180ksi bolt

another day in paradise, or is paradise one day closer ?

 

[Sid89]

Guys,

Thank you for the response.

This question was related to high strength bolt material for valves to be mounted on spacecrafts. We design and manufacture valves and our customer wants to upgrade the bolting material for their valves so that they can withstand aerospace temperature pressure requirements. This is a new project for us so we are still searching for capable bolt materials.

 

[rb1957]

Avoid High-strength Steel, what you gain in Ftu you pay for in fatigue/toughness.

In space Ti bolts could be preferred (less thermal effects).

There should be plenty material out there on "spacecraft" bolts.

I note you did not say where you are, what country ?

Has your customer given you a specification to meet, or just said "we want more" ?
How do you know your current bolts are not good ?

another day in paradise, or is paradise one day closer ?

 

[Compositepro]

rb1957 if you want to know where a poster is from click on their name and to see their profile and location. South Carolina.

 

[rb1957]

uhmm … see profile, not location. Oh, I see now (NC, US)

another day in paradise, or is paradise one day closer ?

 

[WKTaylor]

side89...

Your requirements mandate expertise in spaceflight materials and hardware. IF your company currently makes spaceflight parts and components, then one [or more] spaceflight experienced M&P engineers on-staff should be the ones to determine what to use... and know the appropriate testing to validate initial design goals.

As RB1957 implied... valve and its internal components do not work in isolation relative to the vehicle and its dynamic systems.

The reason for this is that operational environments [temperatures, chemistry, flows, materials in-contact, etc] can vary wildly... and each combination of factors has to be validated.

There are available NASA reports for valve and component design related to high rate-flows of various cryogenic fluids.

NOTE. Materials problems are likely to be Your least problems... the worst problems may include non-materials factors, such as vibrations/flutter, galling/fretting/spalling, friction, thermal shock, high-rate-wear, etc... just to name a few mechanical factors.

Regards, Wil Taylor

o Trust - But Verify!
o We believe to be true what we prefer to be true. [Unknown]
o For those who believe, no proof is required; for those who cannot believe, no proof is possible. [variation,Stuart Chase]
o Unfortunately, in science what You 'believe' is irrelevant. ["Orion", Homebuiltairplanes.com forum]

 

[tbuelna]

Sid89,

A great place to start your research is the NASA Fastener Design Manual.

https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19900009424.pdf