IS 4205:1989 is the Indian Standard (BIS) for drafting stools-specification. This standard specifies the requirements for materials, dimensions, manufacture, and finish of drafting stools used primarily in drawing offices, architecture studios, and educational institutions.
Drafting stools-Specification
| Parameter | IS Value | International | Source |
|---|---|---|---|
| Static Seat Load Test | 110 kgf (approx. 1079 N) | 11,120 N (2,500 lbf) for proof load on the base. | ANSI/BIFMA X5.1-2017 |
| Seat Height Adjustment Range (Type 1) | 560 mm to 760 mm | Specifies a seat height range 'h' for a work chair, which for high stools is typically 560mm - 850mm. | EN 1335-1:2020 |
| Base Spread (Min. Diameter for Swivel) | 600 mm | Not specified prescriptively; the base must be large enough to pass all stability tests. | ANSI/BIFMA X5.1-2017 |
| Seat Diameter (Minimum) | 300 mm | 400 mm (minimum seat width) | EN 1335-1:2020 |
| Stability Test Method | Withstands 2 kgf (19.6 N) horizontal force at seat edge without tipping. | Must not tip when a 20 lbf (89 N) horizontal force is applied to the backrest (Rear Stability Test). | ANSI/BIFMA X5.1-2017 |
| Foot Ring Strength Test | No specific strength test defined; considered part of the overall structure. | Must withstand a vertical static load of 136 kg (300 lb) without failure. | ANSI/BIFMA X5.1-2017 |
| Backrest | Optional; if provided, must have a minimum size of 250x120 mm. | If present, must pass extensive strength and durability tests (e.g., 120,000 cycles of 334 N force). | ANSI/BIFMA X5.1-2017 |