2025/011
A “Shetak”Engineers DTC Chart Circular Conversion Gauge
c.1939
A “Shetak”Engineers DTC Chart Circular Conversion Gauge in the form of a slide rule (or sliding chart) in plastic used to determine the correct drill sizes for tapping and clearance when working with different thread types (Whitworth and Metric) and gauge bolts.
| Acquisition Number | 2025/011 |
|---|---|
| Item Type | |
| Short Description | Shetak slide rule |
| Manufactured by | |
| Date of Manufacture | c.1938 |
| Sub-items | None |
| Supporting Items | None |
| Makers Number | None |
| Marks | None |
| Dimensions (mm) | 95 (dia) x 25 |
| Donor | |
| Date Donated | July 2025 |
| Materials | Plastic |
| Condition | Good |
| Display Location |
