Schwenk measuring instrument with analog dial indicator for internal measurement, 280-410 mm, measuring depth 750 mm

Description

Schwenk internal measuring instrument for large depths, measuring range 280 – 410 mm, depth 750 mm is a Schwenk two-point internal measuring instrument extended for deep holes — featuring a long handle and probe rod that reaches into holes far beyond the working depth of a standard internal measuring instrument. The two-point measuring head is located at the far end of the probe rod, opposite a dial indicator at the operator’s end; the operator zeroes the indicator on a setting ring at the nominal diameter and then reads the hole difference directly as the head is passed through the hole.

Schwenk’s two-point measuring principle uses two opposing contacts — one fixed reference and one spring-loaded probe — that ride against the hole wall. As the head is passed through the hole, diameter variation, ovality, taper, or ”barrelling” is displayed as dial rotation on the indicator at the handle. Resolution depends on which dial indicator is mounted; typical values are 0.001-0.01 mm per division.

The 750 mm reach is the constructed length of the handle/rod unit — the maximum depth from the hole opening where the measuring head still sits orthogonally in the hole. Suitable for hydraulic cylinder bores, long bushings on conveyors and gearbox shafts, deep hole inspection on machine tools, oil and gas pipe bores, and all holes where the inspection point is beyond standard reach.

Usage: select a setting ring at the nominal hole diameter, zero the dial indicator with the head seated in the ring, then pass the head through the hole. Note the dial rotation at several positions along the hole length to map taper, ovality, and form. The Schwenk STANDARD LINE handle is hardened, ground, and dimensionally stable over temperature.

Features

• Schwenk two-point internal measuring instrument with extended rod
• Measuring range 280 – 410 mm
• Reach 750 mm
• Two-point opposing-contact measuring principle
• Compatible with standard Schwenk dial indicator (sold separately)
• Setting ring zeroing for direct deviation reading
• Hardened, ground, dimensionally stable rod and handle
• STANDARD LINE build quality
• Suitable for hydraulic cylinder, long bushing, and deep hole inspection

Specifications

Compatible accessories

Schwenk dial indicator (matched to desired resolution per division — typically 0.001 mm or 0.01 mm). Setting rings at nominal hole diameters over the 280 – 410 mm measuring range, for periodic zero verification and traceable calibration. Schwenk extension rods and handle adapters where deeper reach is required than the standard 750 mm configuration. Calibration certificate (ISO 17025) at first delivery and periodic verification. Wooden case for protection and bench storage.

Additional information