Mitutoyo 550-311-20 ABSOLUTE Digimatic Caliper

Technical Overview

IP67 digital 0-8"/0-200mm nib-jaw caliper with ±0.0015" accuracy, SPC data output, and ABSOLUTE linear scale. Ideal for high-precision inside bore metrology.

Key Features

Rounded nib-style jaws designed specifically for highly accurate inside diameter (ID) measurements
IP67 protection level enables dependable use in environments exposed to coolants, cutting oil, water, and heavy dust
ABSOLUTE linear encoder system delivers reliable measurements without the need to repeat zero-setting at power-on
Integrated SPC data output port supports real-time data export to statistical process control networks
Hardened, corrosion-resistant stainless steel main beam and slide construction ensures long-term industrial durability
OFFSET function automatically compensates for the inner jaw thickness (10.26 mm) during internal diameter measurements
Easy-to-read high-contrast LCD screen with a clear digital step of 0.01mm / 0.0005"

Technical Specification Matrix

Parameter	Value
Measuring Range (OD)	0 to 8 inches (0 to 200 mm)
Measuring Range (ID)	0.404 to 8.4 inches (10.26 to 210.16 mm)
Resolution	0.0005 inches (0.01 mm)
Accuracy	±0.0015 inches (±0.03 mm)
IP Rating	IP67
Jaw Length	60 mm
Position Detection Method	ABSOLUTE electromagnetic induction linear encoder
Max. Response Speed	Unlimited
Data Output	Yes (SPC Output)
Battery Type	SR44 (1 pc.)
Battery Life	Approx. 5 years under normal use
Construction Material	Hardened Stainless Steel
Physical Weight (kg)	0.18
Dimensions L x W x H (cm)	29 x 7.6 x 1.6

Industrial Applications

1. Precision Aerospace Bore Inspection

Utilized in checking the internal dimensions of machined landing gear components and aircraft hydraulic cylinders where high tolerance limits are strict.

Problem Solved

Standard caliper jaws cannot correctly align with deep curved inner walls, causing misalignment and error. The 550-311-20's rounded nib jaws seat perfectly against curved surfaces for exact point-to-point internal diametric reading.

Bore MetrologyInside DiameterInternal CalibrationAerospace Machining

2. Automotive CNC Shop Floor Quality Assurance

Direct, station-side inspection of engine blocks, transmission cases, and deep seal-ring channels where coolant fluid spray and metallic dust are heavily present.

Problem Solved

Standard digital tools fail rapidly when exposed to conductive liquids or dust particles, and manual hand-logging of data is slow and prone to transcription errors. The IP67 rating ensures continuous operation in coolant-heavy environments, and the SPC output enables immediate digital logging to quality networks.

Coolant-ProofCNC Quality ControlSPC Data IntegrationShop Floor Inspection

3. Hydraulic Actuator Seal-Groove Verification

Verifying high-tolerance internal seal grooves on heavy industrial actuators during preventative maintenance and rebuild routines.

Problem Solved

Technicians must manually calculate the thickness of internal jaws when trying to determine internal channel dimensions, introducing potential arithmetic errors. The dedicated OFFSET button on this model automatically accounts for the jaw thickness (10.26 mm) for direct on-screen measurement display.

Seal GrooveOffset CompensationIndustrial MaintenanceActuator Tolerances