Sweet Little 1/2" Micrometer

At our clubs resent clubs auction night, where members donate unwanted item to be auctioned off for club funds, as the action was coming to an end a lot of miscellaneous item came under the hammer there were all sorts of bits of bobs in it that included sealing wax and a 1/2" micrometre, now 1/2" mics are unusual I have only come across one before that belonged to an old work colleague, he kept it in his draw using it from time to time as the need arose, knowing he had it I also borrowed it, there was something real sweet about it just fitted in your hand. Before a could place a bid someone piped up I'll give you £4 as I need the wax, bang it was sold. I asked the buyer if he would sell me the mic, no I won't sell it i'll give it you he said and handed it to me, so in the sprit of the occasion I put £1 into the club pot.

It was made by a firm called ROBBLAK (never heard of them) it has a previous owners name lightly engraved in it G.Haris. and on the other face its stamped up as FOREIGN No 502 and it has a company calibration reference number etched 4D

I've since found out that the firm Robblak were Roberts, Black and Co., 19-21 Brazennose St. Manchester 2. They were advertising a hand shaper which looks like a pre Great War design in ME in 1950.

When I got it home I stripped it down and stuck the parts in my ultrasonic cleaner to get rid of the gunk, I then put it back together gave it a squirt of WD40 zeroed it up checked it across its range with slips, it was spot on the locking ring works and the ratchet was nice and sweet. It now sits on my desk where I find myself handing and as a kind of comforter. Its a real nice bit of kit just to hold:-

Yes I know I'm a sad old bastard but I just love tools.

Stew

You can get mini micrometers from MSC Industrial Supply Ltd. (UK) . The manufacturer is SPI and they are good quality & presented in little wooden boxes. Price is around £19 each.

SPI no. 13-790-1 MSC no. SPU-13790K 0-0.6" 0.001" divs.

SPI no. 13-604-4 MSC no. SPU-13606B 0-15mm 0.01mm divs.

Brown & Sharpe, who claim to have produced the first practical micrometer, used to list various 1/2" models and the Robblak example is very like some of their pre-war offerings. Remarkable that the Robblak has retained its accuracy - is the fixed anvil removable as the slotted screw suggests and did you disturb it when overhauling the mic?

One of our club members had a "going out of business" sale, and had a cute little Starrett 0-1/2" micrometer, in box, for a really low price.

Did not pick it up (do everything in metric, so it would have sat for decades) but a club member who is not metrified picked it up and is as happy as a clam with it.

Now, if it had been a 0-15mm micrometer, a fist-fight would surely have ensued!

(actually, probably not - I'm the only one who measures everything in metric in our club)

Another JohnS.

With regard to the item being made in Manchester and then marked up as "foreign"; perhaps the original owner was a Yorkshireman.

Uncommon but not that rare in my experience. Several available on eBay right now including M&W, B&S, "Handi-Mike", J.T.Slocomb, Starrett.

I saw a M&W one at a local flea market some months ago.

Stewart Hart

Thanks for the further information. Having only a faint recollection of the Robblak name, it never occurred to me that they might not be the makers but it's certainly not a name I associate with mics. The position of the engraving looks right for the maker so could it have been over-written? That seems unlikely, which perhaps leaves the identity of the maker a bit in doubt. That said, there were at one time a great many tools on the market which were simply labelled "Foreign" but I can't call to mind the background to this practice.

Anything you measure with it will never know the difference!

PS There is a very similar Starrett no 219 mic on eBay - buy it now at £75!

I hope I'm not retreading old ground but if you are interested in micrometers check out the COFES micrometer website- a very fine collection which is well documented.

jonathan heppel:

Thanks for the COFES reference; albeit "incomplete" it seems significant that it does *not* include Robblak in the list of makers.

Stewart Hart:

Sounds convincing. If this was before American entered the war was the "foreign" label adopted to maintain the appearance of neutrality? You need more than guns to wage war. I gather that paper and rubber were also vital.

Very neat Stew.

My immediate reaction was 'Robblak used to advertise in ME!' but you got there first.

Neil

A rather belated addition to this thread - I read Stuart's original post with interest and it also triggered a memory of a tiny micrometer that I had when I first started model engineering and long since superceded by more modern and larger models.

This appears to have no markings on it at all, of brass or perhaps gunmetal construction. It appears to be an extrusion from some angles and also suggests being hand finished - there is a curious flat under the frame threaded section for instance.

Once I found it again, I cleaned it and dropped it into the ultrasonic tank for a final clean followed by a drop of clock oil to lubricate the thread (stand by to be told that this is the last thing to use!). The anvils are pitted but clean and it still zeros at close. However it is not so good at the other end of the scale, measuring a nominal 10mm shaft it reads 10.03 whereas my digital mike shows 9.99. At mid point the error is halved so it appears to be linear. BTW, I have never adjusted it so I cannot be held responsible for the chewed up adjuster screw head.

Working on the idea that it may be hand made makes me wonder if the measurement error is also caused by inaccuracies in marking out or the quality of the screw threads.

Anyway, it will be returned to my measuring tools box in a much tidier state than it left!

Simon

That is a neat little job Simon, could very well be home made a lot of the old industrial firms use to make their own specialised kit.

My uncle Arthur was a tool maker at Crewe Loco works and I can remember him saying that they made their own specialised micrometres for getting into hard to reach places, I don't know if this was just the frame with a bought in thimble or if they made the lot, the thimble thread is 5/16"*40tpi ME so I guess most model engineers could nock something up, the hardest part would be lapping the anvils perfectly flat and square.

I have some of my uncles tools and use them regularly.

Stew

Simon I have an almost identical one but made of steel and it is metric I also have a 1/4 inch Brown and Sharpe

Is it just me or do other people find that quality, old, well used tool feel right when you use them? Whereas new tools feel that they need ' working in ' I have several old hammers , an old hacksaw and a couple of old files that almost seem to work themselves

Roy