Hex Head Bolt readily available in US with 12.9 equivalent rating or +

[ExDrill]

Hi,
We are currently searching a fastener, that is readily available in the USA in quantities of 50 maximum say, with a hex head and nut that has a 12.9 or equivalent tensile strength. I come from an Australian engineering background and am unfamiliar with the USA market. I am only familiar with 10.9 that we sometimes use on trucks. Currently we buy Unbrako brand socket head cap screws (to achieve the greater strength of 12.9) and the question came up from my boss who detests them due to their serviceability in the field requiring special allen type keys wrenches. Maybe this is a question for the aeronautical boys but then again they probably only use titanium and aluminium due to the cold temp.

Really we would prefer the UNC thread form due the availaility of 2H and equivilent nuts.
Cheers,
Exdrill

 

[WillTheThrill]

mcmaster.com ?

 

[ornerynorsk]

I believe you are referring to "Grade 8", which is very roughly equivalent to the metric 12.9. Do check your tensile numbers, though, to be safe!

Any good local hardware store, farm/fleet supply, and the like will carry these fasteners, as does McMaster Carr, which Will posted.

It is better to have enough ideas for some of them to be wrong, than to be always right by having no ideas at all.

 

[swall]

No, SAE grade 8 is equivalent to metric 10.9.

 

[ExDrill]

Thanks for the feed back guys but grade 8 is the approx equivalent to 10.9 and mcmaster only has grade 10.9. See this guys

http://www.americanfastener.com/technical/grade_markings_steel.asp

american fasteners fabricates bolts only up to 150000 psi or grade 8. I need 12.9 which has approx 20% higher tensile strength

I found a company SPS which supply the unbrako brand capscrew and they have umpteen amounts of aviation bolts with high tensile strengths and hex heads. Ill give them a call and let you all know of the availability to the public but this is all I can come up with.

Another great question (for me anyway), Has anyone heard where to buy alloy bolts grade 14.9 (see this thread where the guy mentions it as though they are popular thread725-68155)? Thats a serious bolt. I'm not galvinising them so I'm not worried about his hydrogen embrittlement issues.

 

[ornerynorsk]

Sorry guys, my mistake. That's what happens when you go from memory on things that haven't been used in awhile :>(

It is better to have enough ideas for some of them to be wrong, than to be always right by having no ideas at all.

 

[ornerynorsk]

There is a grade 9 with limited size availability. Strengths are in the neighbourhood of 180ksi. You did say you were searching for UNC imperial sized bolts? If I'm not mistaken (again) McMaster Carr might carry these, as well. Good Luck!

It is better to have enough ideas for some of them to be wrong, than to be always right by having no ideas at all.

 

[ExDrill]

Nice, Ill have a look! Thx.

Just had a look and their zinc plated. Anyone know if you can get them in black. Hydrogen embrittlement is a killer!!

Great to know of the grade 9 (which is approx 12.9) though!

 

[SnTMan]

ExDrill, in ASME materials SA-574 and SA-540 offer strengths close to 12.9 strengths, although a little low on the yields, say 150 ksi vs 160 for 12.9.

Don't know if they are readily available.

Regards

Mike

 

[ExDrill]

fyi

http://www.f911.com/fore2b.html

They offer in black
Ill call and see if they are readily available and get back to you all.

 

[ornerynorsk]

Properly processed during manufacture, hydrogen embrittlement is supposed to be mitigated on high strength hardware. This is a little bit outside of the realm of my knowledge, however. Could you have them stripped and use them in-the-white?

It is better to have enough ideas for some of them to be wrong, than to be always right by having no ideas at all.

 

[ExDrill]

Black is as quenched so good for me. Its the zinc processing after manufacture that needs the mitigation. Youll see in my link that the yellow zinc coating is specified with a post heat at 300 and something degrees to burn off all the hydrogen supposedly. I just want black and paint it as Ive heard horror stories of how that can still go wrong. Its not as though that dismal thin zinc coating helps in most applications anyway. They seem to rust out about the same.

 

[rmw]

Here is a selection. See if you can find anything that might suffice.

http://www.portlandbolt.com/technicalinformation/fastener_identification_markings.html

rmw

 

[dinjin]

You want a stronger bolt because the guy does not want to buy allen wrenches? I guess your design parameters are such that you cannot turn the nuts and must turn the heads. Are the allen wrenches breaking? Were the socket head style designed because you could not get enough wrench clearance to use the larger heads?

 

[Tmoose]

hmmmm.... if a special allen socket wrench creates assembly problems, how do they feel about those pesky torque wrenches and turn-of-the-nut indicator wrenches?

 

[unclesyd]

I would checkout ARP for your requirements I know they have external wrenching, spline type head. With my slow computer I have hard time negotiating their site. You might have to give them a call. Nearly every automotive speed shop carries their products.

http://arp-bolts.com/

You are getting in the tensile range and depending on your application that may require an external wrenching head other than hex. Our cutoff for hex head bolts was nominally 160,000 psi tensile where we started to require external wrenching bolts or nuts, in our case it was the "Super Torque Head. Any tensile strength above 125,000 psi we require only 6 point tools.

 

[ExDrill]

Valuable post unclesid now we are talking...

I thought a hex socket was a 6 point tool though??? being a hexagon with 6 sides.

For the record guys, in the back blocks of africa only a select few carry allen keys and sorry I cant choose our clients, they choose us.

Unclesid might be onto it though. If I cant have a hex head I have to redesign and go bigger and grade 5, sorry boss!!!

 

[osoloco]

I agree that it may be time to rethink the use of ultra-strength bolts if you are in the bush. I used to buy grade 8 bolts from Caterpillar, pricey but they came individually boxed....
Seriously, machinery, automotive & farm equipment suppliers generally have a supply of quality fasteners.

 

[unclesyd]

You might also want to look at the Supertanium line of cap HHCS from the Premier Group. The Supertanium name has been bounced around a lot but it looks like it might back under the Premier name. I would give them a call for more technical data.

http://www.gwinnupcommunications.com/PF_Online/scstore/c-SupertaniumAmAj174AwHex1.html

You might want to read the following thread in its entirety for more information. At the time Lawson Products was carrying the fasteners.

thread725-95071

 

[unclesyd]

After thinking about it for a few seconds think your idea of going to a larger lower grade bolt might not be too bad if as you posted this equipment is going to be used from from source of the high strength fasteners. Murphy will show his hand.