| Year | 1932 |
| Weapon Type | Medium Mortar |
| Origin & Designer | Britain-France-Poland/FSMP |
| Numbers Produced | 900 |
| Crew | 6 (Team Leader/Aimer, Gunner, Loader, 3 x Ammunition Men) |
| Calibre | 81mm |
| Elevation | +45° to +88° |
| Traverse | +8° to +12° |
| Cartridge Weight | [@cartridge_weight] |
| Round Weight | 3.2 kg & 6.5 kg |
| Barrel Length | 1.260mm |
| Overall Length | [@length] |
| Grenade Types | [@grenade_types] |
| Mount | [@mount] |
| Combat Weight | Total: 60 kg 20 kg (Barrel) 18 kg (Base Plate) 22 kg (Bi-Pod) |
| Operation | [@operation] |
| Cooling System | [@cooling] |
| Sights | [@sights] |
| Feed | [@feed] |
| Practical Rate of Fire | 12 r.p.m. |
| Maximum Rate of Fire | 20 r.p.m. |
| Blank Cartridge | [@blank_cartridge] |
| Muzzle Velocity | 210 m/s (3.2 kg) 115 m/s (6.5 kg) |
| Fuel Capacity | [@fuel_capacity] |
| Minimum Range | 240m (3.25 kg) 95m (6.5 kg) |
| Effective Range | [@effective_range] |
| Maximum Range | 3.120m (3.25 kg) 1.200m (6.5 kg) |
| Armour Penetration | [@armour_penetration] |
| Bayonet | [@bayonet] |
| Traction | [@traction] |
| Variants | [@variants] |
| Notes | The Wz.31 was a medium mortar which was based on the Stokes/Brandt design. These weapons were built under licence in Poland and was issued to mortar platoons located in heavy machine gun companies, which were organic to each battalion. |