From: "Nat Puffer" Subject: Re: COZY: Prop bolt suppliers Date: Thu, 17 Feb 2000 06:48:32 -0600 Paul, AN bolts have a thread length of about 5/8 inch, which makes it difficult to get good engagement as a prop bolt without bottoming out the threads. Grade 8 industrial bolts have a longer thread, either 1-1/2 or 2 inches, but the threads are cut, rather than rolled, which causes stress risers at each thread, and increases the likelihood for fatigue failure. Sensenich has special propellor bolts made, which have the same specs as AN bolts, but with rolled threads about 1-1/2 inches long. They are expensive, but IMHO better. Regards, Nat ---------- > From: Paul Stowitts > To: Cozy_Builders > Subject: COZY: Prop bolt suppliers > Date: Thursday, February 17, 2000 1:14 AM > > I have checked the archives and I didn't find any thing on where to find > prop bolts. Does anyone have a good lead on this? Are standard AN bolts OK > for this purpose? > > Thanks. > > Paul Stowitts > Cozy mark IV #200 > From: Muzzy Norman E Subject: COZY: Prop bolt suppliers and standards Date: Thu, 17 Feb 2000 10:45:58 -0600 <> SAE Standard for externally threaded fasteners- SAE J429 3.3 Threading Practice- Grades 2,5,5.2, 8, and 8.2 bolts and screws in sizes up to 3/4 in. inclusive, and in lengths up to 6 in. inclusive, shall be roll threaded, except by special agreement. Grade 7 bolts and screws shall be roll threaded after heat treatment. Grade 5.1 bolts screws and sems shall be roll threaded. Threads of all sizes of Grade 1 bolts and screws, and Grades 2, 5, 5.2, 8, and 8.2 bolts and screws in sizes over 3/4 in. and/or lengths longer than 6 in. may be rolled, cut, or ground, at option of manufacturer. Threads of all grades and sizes of studs may be rolled, cut, or ground, at option of manufacturer. Rolled thread bolts are not a rare item, however finding a verifiable rolled thread bolt may be. If you go into your local handy-mart and ask for a bolt that conforms to SAE J429 Section 3.3, they will probably suggest that you get a cherry slushy instead. You cannot (at least I cannot) distinguish between rolled threads or cut threads by visual inspection only. The MSC catalog has bolts that conform to SAE J429. They also carry a Grade L9 Zinc Plated 'for severe service and featuring the highest minimum tensile strength (180,000 psi) and highest resistance to cracking, wear, and metal fatigue ...' NOTE: This is FYI only- standards change and there has been problems with conformance to standards in the past. But then again, a lot of the conformance violations were found in the aircraft business. From: Epplin John A Subject: RE: COZY: Prop bolt suppliers Date: Thu, 17 Feb 2000 11:04:34 -0600 I got mine from Judy Sabre, the prop extension expert. She has different sizes, you need to know what you need, total through the prop, crush plate spinner bulkhead and whatever. She also includes some larger washers that are hardened and ground. Not cheap but good. They are lot traceable. John Epplin Mk4 #467 > -----Original Message----- > From: Paul Stowitts [SMTP:CozyBldr@worldnet.att.net] > > I have checked the archives and I didn't find any thing on where to find > prop bolts. Does anyone have a good lead on this? Are standard AN bolts > OK > for this purpose? > > Thanks. > > Paul Stowitts > Cozy mark IV #200 From: "Paul Stowitts" Subject: COZY: Prop Bolt Suppliers Help Date: Thu, 17 Feb 2000 09:55:23 -0800 Thanks for the help on the prop bolt suppliers. Performance Props had them for $48 plus $6 shipping. I understand Judy Saber also carries them. Paul Stowitts Cozy Mark IV #200 Date: Thu, 17 Feb 2000 12:00:50 -0800 From: Howard Rogers Subject: Re: COZY: Prop Bolt Suppliers Help Wow, Paul! I know this may sound like a strange question, but was that for one, or a whole set? The approved bolts for my Grumman Cheetah were a LOT more than that for just ONE (which is one more reason I'm kinda glad I don't have the airplane any more). -Howard Rogers At 09:55 AM 2/17/00 , you wrote: >Thanks for the help on the prop bolt suppliers. Performance Props had them >for $48 plus $6 shipping. I understand Judy Saber also carries them. > >Paul Stowitts >Cozy Mark IV #200 From: "Nat Puffer" Subject: COZY: prop bolts Date: Thu, 17 Feb 2000 12:03:15 -0600 Builders, Whichever prop bolts you use, whether Grade 8, AN, or Sensenich, it would be a good idea to screw one of the bolts into one of the extension lugs until the threads are bottomed out, then look behind the flange to see how many threads are protruding. Then, when you install the prop, you can again check how many threads are protruding behind the flange, and if less, you can be sure you haven't bottomed out the threads. It's nice to know you are safe. Regards, Nat Date: Thu, 17 Feb 2000 15:33:01 -0600 From: David Domeier Subject: Re: COZY: Prop Bolt Suppliers Help Sensenich sells bolts over the www. A set of six half inch bolts 6.844 long with a grip of 5.300 costs $215.00. The $48 probably is each. dd From: cdenk@ix.netcom.com Date: Thu, 17 Feb 2000 17:36:22 -0500 (EST) Subject: Re: COZY: Prop Bolt Suppliers Help Judy Saber's and Performance prop's propeller bolts to the best of my knowledge (I spoke with Judy Saber directly several months ago) have cut threads, and not rolled threads. All aircraft grade bolts are rolled threads. For a static (bolt itself not subject to pulsing loads) loading, that might be OK, but the loading on a prop bolt is many cycles of various loadings. I did not get the bolts from the previous mentioned sources. All of my bolts for the last several years have been from Sensenich, Spruce (they even drilled the heads), and Skybolt. For the 7/16" bolts the cost typically has been in the $40 -$50 range for 6 pieces. From: cdenk@ix.netcom.com Date: Thu, 17 Feb 2000 17:41:19 -0500 (EST) Subject: Re: COZY: Prop bolt suppliers and standards Was said Caution here, higher tensile strength, could mean a reduction in ductility, and may in fact be brittle. A higher strength material may not be suitable. The strength is attained by various combinations of alloys and heat treatment. Each one is made that way for a specific purpose.