Mailing List flyrotary@lancaironline.net Message #42106
From: <wrjjrs@aol.com>
Subject: Re: [FlyRotary] Re: Metric Bolts
Date: Thu, 27 Mar 2008 12:58:01 -0400
To: <flyrotary@lancaironline.net>
Jarrett raises a good point. Virtually all bolt manufacture is now done by rolling the threads. Thread rolling is a forging process where the die presses a thread into the shank of the bolt. In fact there is even a callout for it in the mechanical engineering world UNFR or UNCR. This refers to a radius formed at the bottom of the thread valley that makes the resulting bolt much stronger than a cut thread, either single-point (lathe) or die cut. Since virtually all bolts are now made this way the R was dropped as superfluous. The point here is if you have a bolt on which the threads are a little... bit short. Use washers! Do not use that tap and die set to cut a few more threads on, you have just weakened the bolt by 50%!
Bill jepson

-----Original Message-----
From: H & J Johnson <hjjohnson@sasktel.net>
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Sent: Thu, 27 Mar 2008 8:20 am
Subject: [FlyRotary] Re: Metric Bolts

One other point which is worth adding. Don't make your own bolts either..
There is a story [old wives tale maybe] going around up here in Canada about a fella who was
a true homebuilder. Made alot of his own bolts from high grade steel.. but cut bolts are a different monkey
from rolled bolts.. [even if they are from 4130 or some such] short version is that he's "headed west" due to a bolt failure.
FWIW
Jarrett Johnson
 
 
>
> Chris,
>
> ?I have to jump in here while I see there are a bunch of other
> replies I simply must chime in.
>
> MOST OF THE CRAP BOLTS SOLD AT THE BOX STORES WOULDN'T QUALIFY FOR
> EVEN GRADE 5!
> <Stepping down from soapbox> The box stores get mass buys and have
> quanties made for them. If you look at the Home Depot free-stock
> bolts they even have a custom headstamp on them. This isn't a
> grade stamp it's a bolt code so the brain dead cashiers can
> quickly figure what to charge for them! Some of the other guys
> have noted the metric codes on their description line so everyone
> should know what to look for.?Aircraft Spruce and Wicks sell good
> quality metric hardware. McMaster-Carr is a big catalog house that
> will sell hardware to the consumer, at a slightly inflated price.
> There is absolutely no reason to have a hardware failure. None of
> us should be using non-AN nuts and bolts for any sagnifigant part.
> Come on guys this is not an area to scrimp.
> Bill Jepson?
>
>
> -----Original Message-----
> From: Christopher Barber <CBarber@TexasAttorney.net>
> To: Rotary motors in aircraft <flyrotary@lancaironline.net>
> Sent: Thu, 27 Mar 2008 5:48 am
> Subject: [FlyRotary] Re: Metric Bolts
>
>
>
>
> Mark,
>
> ?
>
> I ama gussen' that Lynn is talking about the Grade 5 and Grade 8
> (usually gold in color, I think)?hardware that is available from
> Lowes and HD.? IIRC, one of these is comparable to certain Mil
> Spec. It may even be the "lower" Grade 5 which depending on the
> application could be used without issue or great concern.? Of
> course your mileage and comfort level may vary.
>
> ?
>
> That being said, exactly what "standards" are being adhered to and
> who is doing the checking is unknown to me just like my aviation
> parts<g>.? FWIW.
>
> ?
>
> All the best,
>
> ?
>
> Chris
>
> ?
>
> Christopher Barber
> Attorney and Counselor at Law
> 5116 Bissonnet, No 418
> Bellaire, Texas 77401
>
> Serving the Needs of Senior Texans through
> Planning with Purpose
>
> 281-464-LAWS (5297)
> 281-754-4168 Fax
> www.TexasAttorney.net
>
>
> -----Original Message-----
> From: Rotary motors in aircraft [flyrotary@lancaironline.net]On
> Behalf Of Mark Steitle
> Sent: Thursday, March 27, 2008 7:04 AM
> To: Rotary motors in aircraft
> Subject: [FlyRotary] Re: Metric Bolts
>
>
>
> Lynn,
>
> Personally, I wouldn't feel comfortable using the grade of
> hardware typically found at the home stores.? Should be fine for
> plugging up a hole here and there, but not for holding the
> airplane together.? The bolts I bought at the NAPA store were very
> high grade, same?as those from American Bolt.? Not so from Home
> Depot.?
>
> ?
>
> Mark S.
>
> ?
>
> On 3/26/08, Lehanover@aol.com <Lehanover@aol.com> wrote:
>
>
> Lowes has metric bolts nuts and screws.
>
> ?
>
> Lynn E. Hanover
>
> ?
>
> ?
>
> ?
>
>
> In a message dated 3/26/2008 12:37:12 P.M. Eastern Daylight Time,
> msteitle@gmail.com writes:
>
>
> Al,
>
> I found a pretty good supply of metric bolts at the neighborhood
> NAPA store.? They keep the bins behind the counter because people
> tend to rummage through them with no reguard for the next guy.?
> They have
>
>
>
>
>
>
> Create a Home Theater Like the Pros. Watch the video on AOL Home.
>
>
>
>
>
>
>
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