Aug 01, 2017 how to read aerospace bolt head markings. Department of transportation federal aviation administration 800 independence avenue, sw washington, dc 20591 866 tellfaa 866 8355322. Within our industry the first two are the most common. Grade 2 requirements for sizes 14 through 34 in apply only to bolts and screws 6 in. In screws, bolts and studs, these standards refer to thread grade markings, or the standard measurements for thread sizes and dimensions. They want a 10mm diameter hex head cap screw with a. Bolts bolts can be identified by the marking s located on the head of each bolt. Ca 90405 fabristeel products inc 22900 w ei ht mile rd. As the jo bolt is installed, the bolt is turned while the nut is held. In addition to the mandatory markings, certain manufacturers may include additional markings to distinguish them from others.
Bolt head markings and what they mean wilsongarner company. A325, a490, and markings to classify the type of bolt type 1 or type 3. The part must be checked thoroughly during production, and the entire history of the part must be recorded. Construction bolt head identification markings guide. A popular misconception is that the dash number gives the shank length in full inches plus eighths of an inch 15 would mean 1 58 shank length. The fatigue characteristics of aircraft grade bolts are superior to other bolts and allow longer safe service life under cyclic loads like those experienced in aircraft. Grade bb bolts, studs alloy steel, quenched and tempered 1.
An bolts are manufactured to the armynavy military standard, predecessor to milspec ms and national aerospace standard nas which followed. Steel 67623 b 8 x symbol for identification of grade, i. Astm a563 grade dh or a194 2h heavy hex sae j429 grade 8. Tds005a 21508 bolt identification and grade markings.
Hex bolt identification, markings and strength chart. The markings shown for all grades of a194 nuts are for cold formed and hot forged. Aircraft hardware is discussed in detail in the structural hardware manual, navair 01. The bolts are centerless ground and threaded after heat treatment. This causes the sleeve to expand over the end of the nut, forming the blind head and clamping against the work. These radial lines indicate that the bolt is a grade 8 bolt. Mechanical properties proof loadpsi yield strength min psi tensile strength min psi nogrademark sae j429 grade 1 bolts, screws, studs low or medium carbon. Hex bolt identification, markings and strength chart table. Aerospace grade means that the materials and process used to create the part are suitable for use in aircraft parts. They are made of low to medium grade carbon steel, the head has no markings. Scroll the fastener head identification or go to the alphabetical link showing the first letter. Here we have a bolt head with the wilsongarner manufacturer mark and six radial lines. Should you find any errors omissions broken links, please let us know feedback. Fastener catalog an3 thru an6 steel, cres or aluminum bolt machine, aircraft, hexagon head ansi b18.
The three principal parts of a bolt are the head, grip, and threads, as shown below. These bolts are the common shiny silver zinc bolts that are used for general purposes. Fastenerdata head markings fastener specifications. Grade a325 carbon or alloy steel with or without boron. Head marking grade and material nominal size range inches proof load psi min.
Threaded fasteners and rivets are identified by air forcenavy an, national aircraft standard nas, and military standard ms numbers. Chapter 6 aircraft hardware because of the small size of most hardware items, their importance is often overlooked. An bolt selector hex head aircraft bolts are made of highstrength type 4037 or 8740 alloy steel type 8740 is most commonly used. Bolts can be made from many materials, but most bolts are made of carbon steel, alloy steel, or stainless steel. Nogrademark, sae j429grade 1, bolts,screws,studs, low orappendix c bolt grade markings and strength chart. The following are to links of aircraft and military ms and nas part identification resources, tools, articles and other useful data.
The safe and efficient operation of any aircraft is greatly dependent upon correct selection and use of aircraft structural hardware and seals. In addition to the indicated grade marking, all grades, except a563 grades o, a and b, must be marked for manufacturer identification. The hex head aircraft bolt an3 through an20 is an allpurpose structural bolt used for general applications involving tension or shear loads where a light drive fit is permissible 0. Bolts an hex head bolts an bolts, regular an close tolerance bolts drilled head engine bolts an clevis bolts an eye bolts ms bolts 12 point bolts drilled head engine bolts hex head cap screws hitemp 1200 degree internal wrenching bolts other nas bolts hex head, close tolerance adjustement fully threaded heat resistant non magnetic. Aircraft and military ms and nas part identification guide. Grade marking required markings astm a 193 grade b8 class 1 regular series and heavy series. Titanium and aluminum bolts have limited usage, primarily in the aerospace industry. Tensile strength psi mpa us bolts no markings grade 2 low or medium carbon steel 14 thru 34. The hex head aircraft bolt an3 through an20 is an all purpose structural bolt used for general applications involving tension or shear loads where a light drive fit is permissible 0.
In 1987, head marking requirements changed from requiring no grade identification to requiring a 307a marking on the head in addition to the manufacturers identification. Bolt grade markings and strength chart mechanical properties head marking grade and material nominal size range inch mm proof load psi mpa min. The jo bolt consists of three parts a threaded steel alloy bolt, a threaded steel nut, and an expandable stainless steel sleeve. Stainless steels include both iron and nickelbased chromium alloys. Aircraft hardware threaded fasteners part two bolts. The tests and paperwork often account for most of the cost of the part. Skybolt anmsnas fastener index please click on page number to view desired page product page product page product page product page a aeroduct 145 b bolts, airframe 9091 ms20219 143 nas697 101 aeroquip hose 34 clevis 93 ms20220 143 nas697nas698 102 aloc fasteners 48 close tolerance 9295 ms20221 143 nas1023nas1025 102. Grade markings and mechanical properties of steel fasteners. Common automotive fasteners guide napa know how blog. An320 96 b bolts, airframe 9091 nyloseal 6 an340 98 clevis 93 polyflow 6 an345 98 close tolerance 9295 pvc fittingshose 5 an345 98 drilled head 92,95 i instrument, nuts 104 an350 96 external wrenching 95 screws 1081 an360 96 eyebolt 93 k kits hardware 124127 an361 100 internal wrenching 95 l lockwire 1. The heads of different fasteners can be stamped with a wide variety of markings onto the head. Hex bolt identification, markings and strength chart table guide. The illustration below, depicts typical and common aircraft an and nas type bolts and their identifying markings. Aircraft hardware, by ron alexander zenith aircraft company.
The dimensional requirements are contained in ansi b18. Fully threaded hex bolts are also known as tap bolts. Aircraft bolt identification, guide table engineers edge. Astm, sae and iso grade markings for steel fasteners. If you see no markings at all on the head of a bolt, do not use it.
Some are made for highstrength requirements, while others are. How to read aerospace bolt head markings aerospace. Cirrus airplane maintenance manual model sr22 15 apr 2007 2. The astm requires structural bolts to be distinctively marked. If the next digit is the letter h, then the head has been drilled for safety wire. An bolts come in three head styles hex head, clevis, and nas bolts are available in hex head, internal wrenching, and countersunk head styles. Jul 09, 2009 determining bolt grade and head markings with northeast fasteners on. Mar 01, 2017 in this video, one of our resident fastener specialists talks about the types of materials fasteners screws, nuts, bolts, washers, etc are available in. Strength ratings are as followsproof load max nondeformation. Fasteners special fasteners on aircraft are designed for many different functions. A quick aside you may notice that in the images the wg mark has been moved around a bit to accommodate the grade markings. Patent and trademark office fastener insignia register active insignias oct 30, 2014 status. Aircraft bolts archives wicks aircraft supply company.
Some bolts share identical head identification and have significantly different strengths. Fastener basics bolt depot nuts and bolts, screws and. An345 98 drilled head 92,95 i instrument, nuts 104. Identifying bolt grades and head markings for us grades 2, 5 and 8. Aircraft bolts will always have a marking on their head. On 0t head underside o head federal screw works 2400 buhl b d detroit, ml 4846 for hex head inch and metric connecting rod bolts aall studs threaded end shown head delta in indent bp ot nut 07 0 radial lines 20 apart faber enterprises, inc 2316 lincoln blvd santa monica. In addition to these markings, the head will often have a manufacturer stamp. Identification grade mark specification fastener description material nominal size range in. Additonal information on bolts is located at the bottom of the webpage.
A354 bolts and alloy yes l4 thru ts psi min studs 12s,000 marked on top of head steel, 212 dia bc ys psi tin grade 109,000 for bolts and on one. An bolts are typically cadmium plated for superior corrosion resistance when compared to commercial grade zinc plated bolts. Aircraft quality bolts are made from alloy steel, stainless or corrosion resistant steel, aluminum alloys and titanium. Mudge fasteners wants to help you identify what these head markings are and when youll need to know them. Download a complimentary pdf of our fastener markings chart. Fastener manufacturers product identification starts with the manufacturers symbol marked on the head, all high grade fastener product contains the manufacturers mark along with the material grade. Mechanical properties proof load psi yield strength min psi tensile strength min psi no grade mark sae j429grade 1 bolts, screws, studs low or medium carbon steel 14 thru 112 33,000. You can measure the length of an bolts in a glider with calipers, without removing the bolt from the airframe.
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