IS 4204:1974 is the Indian Standard (BIS) for functional requirements for drafting chairs. This standard specifies the functional and dimensional requirements for drafting chairs to ensure ergonomic support, adjustability, and comfort for draftsmen working at elevated drawing boards.
Functional requirements for drafting chairs
| Parameter | IS Value | International | Source |
|---|---|---|---|
| Seat Height Adjustment Range | 550 mm to 750 mm | Typically 570 mm to 810 mm for high chairs to meet ergonomic principles | BS EN 1335-1:2020 |
| Base Requirement | A five-pronged base is recommended. | The chair shall not have fewer than 5 supporting points and must pass rigorous stability tests. | BS EN 1335-2:2018 |
| Seat Depth | 350 mm to 400 mm | 400 mm to 440 mm (with an adjustment range of at least 40 mm) for a Type A chair | BS EN 1335-1:2020 |
| Backrest Height (above seat) | Minimum 250 mm | Minimum 220 mm (for Type A chair) | BS EN 1335-1:2020 |
| Footrest Requirement | 'Foot-rest... shall be provided' | A foot support shall be provided if the lowest seat height adjustment is > 550 mm. | BS EN 1335-1:2020 |
| Stability Test Method | Simple static proof load applied at the edge of the seat or top of the backrest. | Machine-applied, specified horizontal and vertical forces to determine tipping point (e.g., rearward stability, front-edge overturning). | ANSI/BIFMA X5.1-2017 |
| Seat Width (minimum) | 400 mm | 400 mm | BS EN 1335-1:2020 |