New Calipers

[85lebaront2]

These showed up one day in my FB feed and having had a couple of pairs that quit, these were cheap enough to try. They measure to the nearest .0005" or .01 mm and seem pretty accurate. They are metal which beats the cheapo ones I bought at AutoZone (plastic, no depth capability and only read in .01 inches or .1 mm increments.

[Gary Lewis]

Nice, Bill!  Can't tell the brand, but the accuracy seems good.

[Rembrant]

Nice. I'd be lost without my calipers. I have a similar set...they're just cheap ones, but they've lasted for years and are pretty accurate to this day. I check them every now and then with a 0.003" feeler gauge, and they're usually correct. If they're accurate enough at 3 thou, they're accurate enough for what I usually use them for.

We have nicer ones at work that I have access to, and they get calibrated annually, so if I do need to measure to tighter tolerances, I have had access to them.

[85lebaront2]

No brand name anywhere. Back side has some thread charts including Whitworth. It really does seem like a nice set of calipers, all metal, at least the parts that need to be. It is accurate enough that that is what I measured the seat belt bolts with.

[Gary Lewis]

Whitworth!?!?!?  Only a few of us on here are old enough to know 'bout them.  Or, maybe some that are into bikes.  I'll bet even Matt in the UK doesn't know Whitworth.

On thing I loved about that standard was that the wrench size referred to the diameter of the bolt.  So a wrench marked 3/8 went on a bolt head or nut for a 3/8" diameter bolt.

[kramttocs]

I learned something (many things) new

http://progress-is-fine.blogspot.com/2017/01/the-evolution-of-standard-wrench-sizes.html?m=1

[Gary Lewis]

That's an interesting scan.  (Didn't read it all, but lots of it.)

I wrote a research paper about 15 years ago on the standardization of thread sizes.  Not sure where it is at the moment, but what I found was quite interesting to me.  In the US standardization happened by industry.  For instance, in ship building, in automobile manufacturing, in the aircraft industry, in woodworking, in watch making, etc.  And there were overlaps, with things like one industry having numbered sizes, like 8-32, 10-24, 12-24, and 14-20.

Yes, "14-20".  Not "1/4-20".  Those are two different sizes and came from two different industries.  They look to be the same but a #14 screw is slightly smaller and the nuts won't go on a 1/4-20 bolt.  So when consolidation happened we needed to lose one.  (But I still have 14-20 taps and die.)

Lots of that kind of thing happened as we standardized.  But the real standardization came during the two world wars.  Allies found they couldn't exchange parts.  In fact, they didn't have the right tools to work on each other's gear.  So standardization happened.

[grumpin]

All the foreign built aircraft I worked on were standard, what I would cal SAE. Occasionally you would find a metric part. Saft batteries made in France were metric. There was a fitting on a hydraulic pump on the Beechcraft King Air 350 that was metric. It was foreign made.

Worked on planes from Israel, Italy and Great Britain.

[85lebaront2]

I have a set of British Standard wrenches, they were purchased from Snap-on when I was at Tysinger Motors and need some for Jaguars, MGs and the occasional Mini we got in. So I have British, American and Metric wrenches in my tools. Also a nice set of Skinner Union service tools.

[grumpin]

85lebaront2 wrote

I have a set of British Standard wrenches, they were purchased from Snap-on when I was at Tysinger Motors and need some for Jaguars, MGs and the occasional Mini we got in. So I have British, American and Metric wrenches in my tools. Also a nice set of Skinner Union service tools.

Those are cool tools to have!

I forgot, a German aircraft too.