What do you call a micrometer as described

I am looking for the correct name of a micrometer which has a flat blade that can be used to measure for example behind a piece in the lathe to the face only needs to measure under 1".

It is so I can do a search for them. I do not have a picture as I don't know the correct name for it.

The face of a micrometer is called an anvil.

I think you want a flat or interchangeable anvil micrometer.

I can only find a digital one just now, but analogue ones do exist:

https://www.hroberts-di.com/all-metrology-c49/micrometers-c158/mitutoyo-117-101-interchangeable-anvil-micrometer-0-25mm-p548/s548

Hi Dalboy you can also remove the anvil and screw and use it to measure step size from a face to diamiter or flat face.

David

It might help to know that such micrometers are used to measure the thickness of gear teeth. So, perhaps asking about a gear-tooth micrometer might open a door for you?

Cheers, Tim

A tube micrometer will do the job. The fixed anvil is not a blade but a cylinder at right angles to the axis of the work to be measured.

Andrew

Just to flesh out the above, the OP should be aware that there are micrometers described as 'tube micrometer' that do not have this feature (e.g Mitutoyo 115-302) - they have a spherical fixed anvil coaxial with the moving anvil, so a picture of the item is important as well as the written description.

There is also a legitimate 'blade micrometer', used, for instance, on circlip grooves. By some magic the blade on the moving anvil does not rotate.

Can you elaborate on "behind the piece" and "in the lathe"

To me you could be describing the back of a disc held in a chuck and wanting to measure to it's front which would be the thickness of the disc in which case a standard mic would do.

Or is the back of the piece pushed up against a chuck face and you want to measure how much is sticking out? in this case a depth micrometer would do the job with it's flat foot on the outer face of the work and moving anvil extended to touch the chuck face.

Digi calliper will also do both and have a flatter blade to fit down between two chuck jaws to  the back of a small piece of work. If there is enough gap between the jaws then an interchangeable anvil mic may do as less room is needed due to it's flatter shape than the usual curved so the frame won't hit the chuck face so easily

Edited By JasonB on 03/05/2023 18:53:20

Edited By JasonB on 03/05/2023 19:04:17

I was going to post a picture of my tube micrometer having had supper. But lost enthusiasm; I'll go and start setting up the CNC mill instead.

Andrew

Hi, in my No. 64 Starrett second edition catalogue, there is one shown which is almost identical to the one that DC31k has linked too, they had eight variations depending on which anvils were required, and in May 1968, the price range was from £7.90 to £9.00, but if you wanted a case to keep it in, it was 15p extra. (prices converted to todays decimal coinage) extra anvils were available, and you could make your own anvils of any shape, to suite special jobs.

Regards Nick.

Edited By Nicholas Farr on 03/05/2023 19:23:37

Dalboy,

If you do a Google search for groove micrometer, I think that you'll find what you are looking for. Make sure that you are sitting down and have a stiff whisky to hand before you read the prices,though.

John

Dalboy

Have a look at paper thickness micrometer, this might be what you are describing. They have a disc anvil of approx 25mm dia.

The reference to a picture was advice to the OP - that it would be unwise for him to purchase on the basis of a written description alone.

Thank you every one the item I was thinking of is the type that DC31k and Jason linked to. Yes they are expensive.

I do already own a Mitutoyo tube wall thickness micrometer. Like THIS ONE

I am also looking at the disc micrometers so I can measure groove sizes.

Not a Mic but a hook depth gauge is another option.

You can always push the work back against something resting on the chuck face when you first put it in. Then use a standard depth mic to measure from turned end of work to that same something held against the chuck

If you are wishing to measure how far the work stands out from the face of, say, the chuck, or a chuck jaw, you may be looking for a Depth Micrometer.

Beyond the Thimble, there is failry long blade (Which is the Zero datum ). Rotating the Thimble causes it to move forward and a rod appears from the datum blade.

The graduations on the Thimble and barrel show how far bthe rod protrudes.

Unscrewing the cap at the end of tthe Thimble allows the rod to be changed for a longer one, so instead of measurinh 0-1" it can then measure 1-2", 2-3", depending which longer rod has been inserted.

I find them less easy to read than a conventional Mic, but with care, it is a very buseful tool, essential for measuring dpeths accurately

HTH

Howard.

The one I have is this and it's called Starrett 220XRL-1 Mul-T-Anvil Micrometer, you can often find them on ebay for £40 or so in a box with the bits.

https://www.starrett.com/metrology/product-detail/220XRL-1

...often called 'Uni-mic' (or 'Uni-mike'...). Possibly a name originally used by Mitutoyo.

I foundthe micrometer listings in the Mitutoyo catalogue, you might be able to see the type you want.

**LINK**

Out here , we call them blade micrometers . A 0-25mm is in a frame size of a 25-50.

Some people look for thread micrometers , and then make up the blades or the forms that are needed. I recently bought a blade micrometer 0-25mm from Aliexpress. I am very happy with it. I got it for measuring the taper on crankpins. Mine came with very thin blades of 0.8mm wide.

As I have a nice non rotating barrel analog 25-50 thread micrometer, if I need a very thin or a radiused blade, I can make them for that micrometer too, and use the extra length, to get by the flywheel side.