Arbiter Posted November 12, 2009 Share Posted November 12, 2009 Hi Folks, I have been reading a number of books on aircraft design and construction and all of them say use only aircraft quality hardware. This would seem straightforward, but I am confused. The confusion lies in which specs are the correct to use. Bolts for example are usually called out as AN-something. However, this spec is now supplanted by NASM, but people don't call them NASM-Something, but AN still... Does anyone else find this confusing? Also, I have seen some information that say Milspec is the same as AN... Can anyone provide clarity to this confusion? The reason I ask is because I have hardware libraries that have milspec bolts listed that I can use in modeling and they appear to be similar to AN bolts. I don't want to use the wrong spec bolts, so I was hoping someone could add a little clarity to this issue. Thank you very much in advance! -Chris Quote Chris Zupp ~Aircraft Designer~ Preliminary Design Sequence I: Project Endeavour Aeronautical/Mechanical Engineer Private Pilot Link to comment Share on other sites More sharing options...
Lynn Erickson Posted November 12, 2009 Share Posted November 12, 2009 Hi Folks, I have been reading a number of books on aircraft design and construction and all of them say use only aircraft quality hardware. This would seem straightforward, but I am confused. The confusion lies in which specs are the correct to use. Bolts for example are usually called out as AN-something. However, this spec is now supplanted by NASM, but people don't call them NASM-Something, but AN still... Does anyone else find this confusing? Also, I have seen some information that say Milspec is the same as AN... Can anyone provide clarity to this confusion? The reason I ask is because I have hardware libraries that have milspec bolts listed that I can use in modeling and they appear to be similar to AN bolts. I don't want to use the wrong spec bolts, so I was hoping someone could add a little clarity to this issue. Thank you very much in advance! -Chris the bolts that most are using are purchased from an aircraft supplier and are commonly known as AN bolts. it is a common term that could include many types of special bolts all of which would have a AN number which has been superseded by an MS number (Mill spec). the common AN bolt that most supplier have is a bolt that is made of 8740 steel centerless ground shank, rolled threads, cad plated, 125,000 psi tensile. hex head. may be drilled at on end or the other or both. comes in 1/8" increments with only a short section of threads on the end. there are many other types of AN or ms bolts all of which have there own specs for a special purpose. in our type of aircraft we use the common AN bolts in most applications unless the plans call for a special type AN bolt. I would suggest you get a catalog from Aircraft Spruce or Wicks aircraft so you can see the most common types of bolts that are readily available to the homebuilt aircraft builders. Quote Evolultion Eze RG -a two place side by side-200 Knots on 200 HP. A&P / pilot for over 30 years Link to comment Share on other sites More sharing options...
Arbiter Posted November 12, 2009 Author Share Posted November 12, 2009 Lynn, Thank you very much for the explanation! I've seen the A/C Spruce catalog and the AN hardware they have available. What you described makes sense and based on that I think the 3D library of milspec hardware is equivalent to the AN hardware. I'll do some more checking but I think the library had a lot of the terms you were referring to in you post. Thank you very much for the clarification! -Chris Quote Chris Zupp ~Aircraft Designer~ Preliminary Design Sequence I: Project Endeavour Aeronautical/Mechanical Engineer Private Pilot Link to comment Share on other sites More sharing options...
Dragonflyer Posted November 12, 2009 Share Posted November 12, 2009 First came AN bolts. This stands for Army-Navy. They were tired of planes falling out of the sky, so they sat down and developed aircraft hardware standards. As time passed, and the government grew, the standard became known as Mil-Spec (military spec) Now it's NAS, or National Aerospace Standard. I tried to copy/paste the link, but it didn't work...so just google "an bolts" and go to page 2 of the results. Scroll down to the 4th entry, "Carroll Smith's Nuts, bolts, fasteners and plumbing handbook" Darrell Quote Link to comment Share on other sites More sharing options...
Arbiter Posted November 13, 2009 Author Share Posted November 13, 2009 Darrell, Thank you for the history! I will check out the links in the next few days! Thanks! -Chris Quote Chris Zupp ~Aircraft Designer~ Preliminary Design Sequence I: Project Endeavour Aeronautical/Mechanical Engineer Private Pilot Link to comment Share on other sites More sharing options...
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