Mitutoyo Micrometer Buying Guide: Digital vs Mechanical, Ranges, IP65 and Special Anvils

This guide compares the Mitutoyo outside micrometers we stock, from coolant-proof Digimatic models like the MDC-25PX and MDC-25MXT to mechanical M110, M310 and counter-type M810/M820 micrometers, plus blade, spline, point, spherical and ball-gear types. Every value below comes from the specification list on our product pages. Where a page does not state a value, we write "Not confirmed" instead of guessing.

Quick answer

Mitutoyo MDC-25PX Coolant-proof Micrometer, 0-25 mm (293-240-30) Mitutoyo MDC-25MXT Coolant-proof Micrometer, 0-25 mm (293-234-30)

• General shop work, wet or dusty floor: a coolant-proof MDC-PX or MDC-MX model. Both series list IP65 and a 0.001 mm display. The 0-25 mm MDC-25PX and MDC-25MXT list ±1 µm.
• You need to send readings to a PC or data collector: choose a model whose page lists a data output terminal, such as the MDC-25MXT or the MD-E25 (two-way Digimatic S1). The MDC-25PX has no output terminal.
• No battery: a mechanical model such as the M310-25 or M110-50 (0.01 mm graduation).
• Finest resolution: the MDH-25MC lists switchable 0.0001 / 0.0005 mm resolution and ±0.5 µm accuracy (values on our page are cited from Mitutoyo distributor listings).
• Grooves, splines, curved walls or gears: a special-anvil model (blade, spline, point, spherical, ball gear or sheet metal). See the anvil section below.

How to choose a Mitutoyo outside micrometer

Work through these six points in order. Each one narrows the list.

1. Pick the measuring range first

Most outside micrometers cover 25 mm of travel, so you buy the range that contains your part size: 0-25, 25-50, 50-75, 75-100 mm and so on. Our coolant-proof MDC-MX line goes up to the MDC-200MX (175-200 mm). Pages for ranges above 0-25 mm list a reference rod in the accessories (for example the MDC-100MX and M110-50), which you use to set zero.

Mitutoyo MDC-200MX Coolant-proof Micrometer, 175-200 mm (293-253-30) Mitutoyo OMST-150B Micrometer Set, 0-150 mm (103-913-40)

One exception: the MDQ Quick Micro models cover 30 mm (MDQ-30MX: 0-30 mm). Also note that accuracy changes with size: the 0-25 and 25-50 mm MDC-PX models list ±1 µm, while the 50-75 and 75-100 mm MDC-PX models and the MDC-100MX list ±2 µm.

If you need several sizes, the OMST-150B set (0-150 mm) and OMST1-300B set (0-300 mm) are listed with a 0.01 mm display.

2. Digital or mechanical

• Digital (Digimatic): 0.001 mm display on every digital model in the table below except the higher-resolution MDH-25MC. The MDC, MDQ, OMV, BLM, SPM, CPM, BMS, GMB and PMU pages we checked list an SR44 battery; the MD-E25 uses a CR2032. Listed battery life is about 2.4 years for most MX models and about 5 years for the MDQ-30MX (capacitive absolute encoder).
• Mechanical: the M110 and M310 series read 0.01 mm on the thimble and need no battery. The M310-25 and M110-50 have carbide-tipped measuring faces.
• Mechanical with counter: the M810 and M820 series add a digit counter to the mechanical thimble reading. The M810-25 reads 0.01 mm; the M820-25 reads 0.001 mm using a vernier scale.

3. Coolant-proof and IP rating

The pages for the MDC-PX, MDC-MX, MD-E25, MDQ-30MX, OMV-25MX, BMS-MX, SPM-MX, CPM15-MX, GMB-25MX and PMU150-25MX list IP65. The MDC-25SX, MDH-25MC, BLM-25MX and the mechanical models do not state a protection class on our pages, so we treat those as Not confirmed.

4. Data output

This is the main difference between similar-looking digital models. For example, the MDC-25PX page states "No measurement data output terminal", while the MDC-25MXT page states "Measurement data output terminal included". Both list 0-25 mm, 0.001 mm and ±1 µm. If you plan to log measurements, buy the output version. The MD-E25 lists two-way Digimatic S1 communication.

5. Ratchet stop or ratchet thimble

Both give a constant measuring force. The MDC-25PX (ratchet stop) lists 5-10 N; the MDC-25MXT (ratchet thimble) lists 7-12 N.

6. Special anvils for special shapes

Mitutoyo BLM-25MX Digimatic Straight-Line Blade Micrometer, 0-25 mm (422-230-30) Mitutoyo SPM-25MX Digital Spline Micrometer, 0-25 mm (331-251-30)

• Blade (BLM-MX, BLM-B): blade-type measuring faces for narrow grooves. The BLM-25MX lists a spindle linear feed mechanism and Type A tips.
• Spline (SPM-MX): spline-type measuring faces of φ3 × 10 mm (SPM-25MX).
• Point (CPM15-MX): point-type tips with a 15° tip angle (CPM15-25MX).
• Spherical (BMS-MX single-sided, BMD-MX double-sided): a spherical measuring face (carbide-tipped on the BMS-25MX) for curved surfaces such as the inside of a pipe wall. The BMS-25MX lists a minimum measurable inside diameter of 15 mm.
• Ball gear (GMB-25MX): precision steel balls on both faces to measure the over-pin diameter of gears (GMB-25MX).
• Sheet metal (PMU150-MX): a 150 mm frame depth, so you can measure away from the sheet edge (PMU150-25MX).
• Straight-type (OMV-MX): a spindle linear feed mechanism with a φ6.35 mm spindle (OMV-25MX).

Comparison table: representative Mitutoyo micrometers

Model	Order no.	Range (mm)	Resolution (mm)	Max. error (µm)	IP / coolant	Data output
MDC-25PX	293-240-30	0-25	0.001	±1	IP65	No terminal
MDC-25MXT	293-234-30	0-25	0.001	±1	IP65	Yes
MDC-100MX	293-233-30	75-100	0.001	±2	IP65	Yes
MD-E25	293-140-40	0-25	0.001	±1	IP65	Yes (Digimatic S1, two-way)
MDC-25SX	293-821-30	0-25	0.001	±2	Not confirmed	Not confirmed
MDH-25MC	293-100-20	0-25	0.0001 / 0.0005	±0.5	Not confirmed	Not confirmed
MDQ-30MX	293-666-20	0-30	0.001	±2	IP65	Yes
OMV-25MX	406-250-30	0-25	0.001	±3	IP65	Yes
M310-25	102-301	0-25	0.01	±2	Not confirmed	Not confirmed
M110-50	103-138	25-50	0.01	±2	Not confirmed	Not confirmed
M810-25 (counter)	193-101	0-25	0.01	±2	Not confirmed	Not confirmed
M820-25 (counter)	193-111	0-25	0.001 (vernier)	±2	Not confirmed	Not confirmed
BLM-25MX (blade)	422-230-30	0-25	0.001	±3	Not confirmed	Yes
SPM-25MX (spline)	331-251-30	0-25	0.001	±2	IP65	Yes
CPM15-25MX (point)	342-251-30	0-25	0.001	±2	IP65	Yes
BMS-25MX (spherical)	395-251-30	0-25	0.001	±2	IP65	Yes
GMB-25MX (ball gear)	324-251-30	0-25	0.001	3	IP65	Yes
PMU150-25MX (sheet metal)	389-251-30	0-25	0.001	±4	IP65	Yes

All models in this table list Japan as the country of origin. "Not confirmed" means our product page does not state that value.

Mitutoyo MDC-100MX Coolant-proof Micrometer, 75-100 mm (293-233-30) Mitutoyo MD-E25 Digital Outside Micrometer, 0-25 mm (293-140-40)

FAQ

What is the difference between the Mitutoyo MDC-25PX and MDC-25MXT?
Both list 0-25 mm, 0.001 mm resolution, ±1 µm and IP65. The MDC-25PX has no data output terminal and a ratchet stop (5-10 N). The MDC-25MXT has a data output terminal and a ratchet thimble (7-12 N).

Is a Mitutoyo digital micrometer more accurate than a mechanical one?
Not automatically. The digital MDC-25PX lists ±1 µm, but the digital MDC-25SX lists ±2 µm, the same as the mechanical M310-25 and M110-50. The main gains of digital are the 0.001 mm display, origin setting and, on output models, data logging.

Which micrometer measures pipe wall thickness or gear over-pin size?
For curved walls, the spherical BMS-MX (single-sided) or BMD-MX (double-sided). For gear over-pin diameter, the GMB-25MX ball gear micrometer.

Do the larger ranges come with a setting standard?
Yes, on the pages we checked: the MDC-100MX and M110-50 list one reference rod (for ranges other than 0-25 mm) plus a spanner.

Related links

• All Mitutoyo micrometers
• Mitutoyo micrometer heads
• The full Mitutoyo range
• Mitutoyo digital calipers compared: CD-AX, CD-APX, coolant-proof CD-P and more
• Which Mitutoyo tool measures what you're working on

All products are genuine Japanese-market stock, shipped from Japan with tracking.