X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml Date: Sun, 08 Oct 2006 17:57:50 -0400 Message-ID: X-Original-Return-Path: Received: from ms-smtp-02.texas.rr.com ([24.93.47.41] verified) by logan.com (CommuniGate Pro SMTP 5.1c.5) with ESMTP id 1449372 for lml@lancaironline.net; Sun, 08 Oct 2006 09:56:15 -0400 Received-SPF: pass receiver=logan.com; client-ip=24.93.47.41; envelope-from=toucan@Satx.rr.com Received: from VAIO (cpe-24-243-1-103.satx.res.rr.com [24.243.1.103]) by ms-smtp-02.texas.rr.com (8.13.6/8.13.6) with SMTP id k98Dtqvk005624 for ; Sun, 8 Oct 2006 08:55:52 -0500 (CDT) X-Original-Message-ID: <004d01c6eae1$61203640$6701f318@VAIO> From: "James Cameron" X-Original-To: "Lancair Mailing List" Subject: Torquing bolts X-Original-Date: Sun, 8 Oct 2006 08:55:13 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_004A_01C6EAB7.77CE4780" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.2869 X-MIMEOLE: Produced By Microsoft MimeOLE V6.00.2900.2962 X-Virus-Scanned: Symantec AntiVirus Scan Engine This is a multi-part message in MIME format. ------=_NextPart_000_004A_01C6EAB7.77CE4780 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable At the risk of huffs and sneers from 'out there,' I think the whole = business with proper torque values is a little overblown. Most of the = fasteners we use have no particular torque specified, including hundreds = of screws and AN3- and AN4- bolts. Sure, you can look up proper torque = values for them in handbooks, but let's face it, most of us just go by = feel. We've been putting things together with bolts and screws all of = our lives, and we learn what feels right for a given type of fastener. = Past experience probably includes more snapped bolts and stripped = threads, or fasteners that backed out or loosened, than we'd care to = think about. Each time that happens, we subconciously file away a = little lesson -- that was too tight, or too loose. For any given size = bolt, we have stored experience that tells us what feels right. It = would be interesting to have some experienced mechanics tighten a range = of fasteners, then go back and somehow measure the torque actually used. = My guess is that almost every one would be within a small margin of = book value. OK, on critical stuff, like prop bolts and engine mounts, we'll drag = out the torque wrench and go by the book. The rest of the time, you = tighten till it feels right. Besides, unless you have a good quality, = calibrated torque wrench, and I mean recently calibrated, it can be so = far off that you'd be better off leaving it in the tool box. Jim Cameron Legacy, N132X reserved ------=_NextPart_000_004A_01C6EAB7.77CE4780 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
    At the risk of huffs and sneers = from 'out=20 there,' I think the whole business with proper torque values is a little = overblown.  Most of the fasteners we use have no particular torque=20 specified, including hundreds of screws and AN3- and AN4- bolts.  = Sure, you=20 can look up proper torque values for them in handbooks, but let's face = it, most=20 of us just go by feel.  We've been putting things together with = bolts and=20 screws all of our lives, and we learn what feels right for a given type = of=20 fastener.  Past experience probably includes more snapped bolts and = stripped threads, or fasteners that backed out or loosened, than we'd = care to=20 think about.  Each time that happens, we subconciously file away a = little=20 lesson -- that was too tight, or too loose.  For any given size = bolt, we=20 have stored experience that tells us what feels right.  It would be = interesting to have some experienced mechanics tighten a range of = fasteners,=20 then go back and somehow measure the torque actually used.  My = guess=20 is that almost every one would be within a small margin of book=20 value.
    OK, on critical stuff, like prop = bolts and=20 engine mounts, we'll drag out the torque wrench and go by the = book.  The=20 rest of the time, you tighten till it feels right.  Besides, unless = you=20 have a good quality, calibrated torque wrench, and I mean recently = calibrated,=20 it can be so far off that you'd be better off leaving it in the tool=20 box.
 
Jim Cameron
Legacy, N132X reserved
 
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