Re: Fastener: SAE vs Metric Metallury 101
- Brown and Sharpe used 1/2" x 12tpi, 60 degree threads for decades even after USS became 1/2" x 13 tpi.KAThis is not right.SAE and Whitworth are not even related to each other.Whitworth and UNC (Unified Coarse) are pretty close, and will screw into each other, more or less.EXCEPT IN 1/2" size, where whitworth is 12 and UNC is 13 tpi (or is it the other way round?)This caused vast problems in the drawbars of tractors for many years.They all seem to use 1/2" bolts.If your american tractor broke its bolts there - as they often do, you CANNOT use british Whitworth to repair it.Or vice-versa.Whitworth has same pitch or screw spiral count as SAE fine or course
so SAE & W can screw into each other but the W has 55' angle
of peaks while SAE 60' so W is stronger in that regard. hobot
- Living in thailand its amusing to see the tools in the local bike repair shops. Most popular being locking pliers, hammers and sacrificial screw drivers to bash axles out.
the Honda shops have a full cabinet of special tools but rarely are they used :-)
Sent: Tue, 03 Sep 2013 7:28
Subject: RE: Fastener: SAE vs Metric Metallury 101
The memory this arouses is an amusing one: Colin Seeley in the late 1960s working on one of his specials incorporate Britshit Standard, Metric and English fasteners. I can't recall whether the particular bike I saw had a Nipponese engine or whether it was the brakes or other bits that required the mm-size spanners. Whitworth galore!
What a nightmare. Here in Indonesia, of course, they have no such problem. Just hand me the "kunci inggris" (the "English wrench"), namely, the adjustable one, ideally the monster about a foot long, so I can attack that devilishly tight 8mm engine bolt.
(I tell the locals my father would have given me a proper beating, and a lecture, and maybe a knock or more for good measure, if he'd ever caught me using one of those on any machine.)
--- In firstname.lastname@example.org, <email@example.com> wrote:Studs with the last thread turned away are also SAE or UNF as they are sometimes termed. - KAAll the chassis bolts went to UNF fasteners, and some of the engine ones too.
Those little overlapping circle symbols mean its UNF.