Hi Graeme,

Most use is measuring 3-flute cutters or similar but here is a link explaining : –

https://www.higherprecision.com/blog/what-is-a-v-anvil-micrometer

I can’t see that the Vee angle is particularly important on these as it is really only to put on a cut not take an actual diameter reading and any reading will deepend on the diameter of the boring bar. Therfore so long as the bar sits nicely in a vee it should work as intended

not take an actual diameter reading

No I said it is just used to put on a cut. The diameter of the bar will affect the zero but as that is not what you are measuring it has no bearing. The angle of the vee will also affect a reading but again that is not what the tool is for

You take a cut with your boring bar and then measure the bore. Work out how much more material is to come off. Then measure the protrusion of the cutter in the bar and make a note of the reading. Bit of maths tells you how many thou you need to advance the cutter in the bar to get to your final bore.

It is no different to doing it with a standard mic but you just get a more consistant measurement due to the vee and have the screw in the valley of the vee to push the tool. I still use this method to know how much to advance the tool when getting close to a final bore.

How do you measure the cut with a simple between ctrs bar if you feel we have no need?

I think you could say Q.E.D. for that one Jason.

Makes you wonder how many times a measurement would have to be taken to get that amount of wear? If you cut a vee into a bit of iron and then rubbed it up and down a bar it would take a lot of time to reproduce those hollows. Unless they just left the mic hanging on the bar while they took a cut!

Building on Bill’s excellent detective work, I think a likely location for the works is the building immediately north of the Brambles:

In later maps it’s extended and labelled ‘Garage’,  so probably started as a commercial building rather than a house.

Pontefract Road is coloured pink: it’s called Barnsley Road on many maps.

Old maps are fascinating.   At one time Cudworth was sandwiched between two large coal mines, one being Grimethorpe of Brass Band fame, and a multitude of railway and mineral lines.

Thanks Bill!

Dave

This is now the 4th attempt

I’m getting ready to give up trying detailed replies on this forum;
Just spent 40 minutes writing a reply only to receive a 403 error on submission saying I no longer have access to this forum and to contact administrators.

I’ll try an abbreviated reply compiled in Notepad;

The various parts, frames & mics, all arrived together, and are obviously quite old, so I can’t definitively state which mic belongs to which frame.
The top right has the same style of ratchet as the rest, but the end cap, screw & pawl are missing, as I moved them to one of the other mic bodies, which was in better condition.
Three mics are M&W with a satin chrome finish; the one currently showing lower right is engraved Ambrose Shardlow, it in a plain steel finish.
It pre-dates GKN-Ambrose-Shardlow, or GKN-Shardlow, (engravings vary) a company which was later absorbed into M&W.

Of the two on the right, the upper one has a lighter frame construction, though is of the same nominal frame size as the lower one; the frame is thinner, as well as having less substantial V sections.
Overall the wear patterns are different suggesting regular use on different boring bars, if indeed that was their use during their working lifetime, as clearly they could be used for different applications.

Top right, the satin chrome M&W body does have loads of deep scratches; I think they are longitudinal scratches/machining marks, rather than compression ones from pliers or similar.
Lower right is in good nick, but harder to read, dues to the lack of satin chrome plating, though it does retain the knurled locking collar, absent from the M&W ones, though they are all threaded for one.
I’m not sure it ever had, or needed a wavy washer, as different mics in my collection vary.

Looking at the engraved sections of the frames, the smallest one seems to have the patent number in a larger typeface, and also the clamping screw features a plain knurling, whereas the rest are diamond pattern.
Maybe this makes it the odd one out, and originally housed the Sharlow mic??
Maybe the original user had loads of them and this is a random mix of parts, as they are all interchangeable.
On the other hand, top right has a lighter frame, so maybe that’s the oddball.

This video, recorded live of a lecture I attended, explains the origins of the three main Sheffield precision measuring companies, M&W, Ambrose-Shardlow, and Chesterman.

p.s. Graeme, I don’t often get up to Holmfirth these days, my friends up there have now moved away, and I now longer visit telephone exchanges since retirement.
If you ever make it to the Peak District, we are in Buxton, so feel free to drop in.

Bill

On 26 June 2025 at 15:14 Graeme Seed Said:

Hi Bill, Thank you so much for a very interesting video. I have a collection of many micrometers and am still after a Starrett 220 which is like trying to find rocking horse ah ah’s. The commentator speaks about digital mics, I thought that this was their name, however, its actually digit [as in numbers]

If you do mean Starrett 220, there’s a couple on ebay at the moment, but more than I’d pay @ £45 & 95
Can’t remember how much I shelled out for mine, which does get a mention in this thread;

Starrett 220 Micrometer?

For non-electronic “Digital” mics, it sometimes helps to search for Direct Reading.
The only UK ones I have are GKN Shardlow Speedread, which I tend to use for most measuring these days.
The metal finish ones seem better made than the green Hammerite paint job ones.
They are based on the Davenport-Williams patent of Dec 1966

https://worldwide.espacenet.com/patent/search/family/003277953/publication/US1210051A?q=US1210051A

I do also have a Slocomb 0-1″ stamped with that same patent (I write stamped, but the lettering is actually raised.)
plus a multi-anvil 0-4″ in a black paint finish, again marked Slocomb, with the same numeric readout.

Bill