1/4x20 AN bolts

[Bill Dicus]

Have been looking for 1/4 x 20 bolts, AN quality, to mount my angled oil filter adapter and spacer(necessary to clear the RV-8 motor mount) and after a few months have nothing but hardware store bolts. Have tried Vans, Spruce, General Aircraft Hardware and many other suppliers found thru Google - no luck. What I need are 1/4 x 20 (not 1/4 x 28, as in AN4 hardware) with grip length of 1.75 to 1.825 inches and at least 3/4 inch thread. Anybody know where to find these? Thanks for any advice. Bill

[scsmith]

Also, there are niffty AN coarse-thread nuts that have a flat mating face on one side - I'd love to find a reasonable source for those. So far the only option I've found is ordering from Lycon using the lycoming part numbers. pretty pricey that way.

[Radomir]

Grade 8 will work just fine.. You can always look into getting some $$$$$$$ bolts from AERO... but I don't think they're any "better"

[frankh]

Get Grade 8 from Napa.

Frank

[Bill Dicus]

Thanks Steve. Will contact Lycon - they built up my engine. Not sure how to get Lyc part #'s, but I hope they can do that. Have a good weekend. How far along are you? Bill

[Mike S]

Try GAHCO.

Tom (owner) is an RVer also.

[robpar]

I did a quick check on AN bolts and found that AN standard is now obsolete and has been superseded by NASM. A search for NASM bolts found this:

http://www.thomasnet.com/products/bolts-6214803-1.html Numerous suppliers.

There are so many standards out there. There is SAE for Automotive and then there is ASME for structural bolts, NASM for aircraft the list goes on and on and is duplicated in metric. All these bolts standards are pretty much the same, strength is pretty much the same, alloys are very similar so as the others have stated use a Grade 8 bolt from any automotive / industrial supplier and you will be more than OK.

Putting a 1/4" Grade 8 bolt through a sheet metal bracket and a sheet metal firewall is over kill. The bolt is so much stronger than any of the other materials it will be the last thing to fail. The threads may loosen but a Grade 8 bolt will not fail in this application.

Bob Parry

[Bill Dicus]

What an amazing resource this VAF is! Should have checked earlier. Thanks to all who responded and will let you know when and if I get the bolts. Bill

[LarryT]

...is essentially an alloy & heat-treat specifications. the spec tells you what strength you should have if the bolt is made right. Unfortunately, Grade 8 is NOT a quality assurance spec. For example, there is no requirement for post heat treating for hydrogen embrittlement of plated bolts or x-ray for inclusions and/or voids. In all the years I raced cars, every critical fastener was AN or a specialty fastener with QA standards & company reputation.

This is just not my opinion, but it is in print in every book published by Carroll Shelby, the individual responsible for the Ford GT finally lasting the entire 24 Hrs at LeMans. The cars had been fast enough for years, but always broke.

His books included "Prepare to Win", "Tune to Win", and a Fastener/Hardware Handbook the name of which I can't rememeber because we all called it Sc**w to Win," a title apparently vetoed by his publisher.

Larry

[Mel]

Be careful using grade 8 bolts in structural situations. They tend to be brittle and have cut threads. AN bolts have rolled threads and are not as brittle.
Do not present an aircraft to me for inspection with grade 8 bolts installed.